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Students can Download Chapter 6 Electro Magnetic Induction Questions and Answers, Plus Two Physics Chapter Wise Questions and Answers helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus Two Physics Chapter Wise Questions and Answers Chapter 6 Electro Magnetic Induction

Plus Two Physics Electro Magnetic Induction NCERT Text Book Questions and Answers

Question 1.
A horizontal straight wire 10m long extending from east to west is falling with a speed of 5.0ms^-1 at right angles to the horizontal component of the earth’s magnetic field 0.3 × 10^-4Wbm².

1. What is the instantaneous value of the e.m.f? induced in the wire?
2. What is the direction of the e.m.f.?
3. Which end of the wire is at the higher electrical potential?

Answer:
I – 10m, v = 5.0ms^-1, B = 0.30 × 10^-4Wbm²
1. Instantaneous value of e.m.f. induced
e = B lv
= 0.30 × 10^-4 × 10 × 5.0
or e = 1.5 × 10^-3V.

2. The direction of e.m.f. is from eastto west.

3. Since the current is flowing from east to west so the eastern end is at higher potential.

Question 2.
Current in a circuit falls from 5.0Ato 0.0A in 0.1s. If an average e.m.f. of 200V induced, give an estimate of the self-inductance of the circuit.
Answer:
dl = l₂ – l₁ = 0.0 – 5.0 = -5.0A,
dt = 0.1s, e = 200V, L=?
Since

or L = 4H

Question 3.
A pair of adjacent coils has a mutual inductance of 1 5H. If the current in one coil changes from 0 to 20A in 0.5s. What is the charge of flux linkage with the other coil?
Answer:
M= 1.5H, dl = l₂ – l₁ = 20 – 0 = 20A, dt = 0.5s, dΦ = ?
Since

And also

or dΦ = Mdl
or dΦ = 1.5 × 20 = 30 Wb.

Question 4.
A jet plane is travelling towards west at a speed of 1800 km/h. What is the voltage difference developed between the ends of the wing 25m long if the earth’s magnetic field at the location has a magnitude of 5.0 × 10^-4 and the dip angle is 30?
Answer:
v = 1800 km/h = 500ms^-1 I = 25m
Vertical component of B along horizontal
B = -Bsinθ = 5.0 × 10^-4 sin30° = 2.5 × 10^-4T
e = B/v sinθ
= 500 × 2.5 × 10^-4 × 25
= 31 V
The direction ofthe wing is immaterial.

Question 5.
Suppose the loop in Q.6.4 is stationary but the current feeding the electromagnet that produces the magnetic field is gradually reduced so that the field decreases from its initial value of 0.3T at the rate of 0.02TS^-1. If the cut is joined and the loop has a resistance of 1.6Ω, how much power is dissipated by the loops as heat? What is the source of this power?
Answer:
Induced e.m.f.

= 8 × 2 × 10^-4 × 0.02 = 3.2 × 10^-5V
Induced current,

= 2 × 10^-5A
Power Loss = I²r = (2 × 10^-5)² × 1.6 = 6.4 × 10^-10 W. Source of this power is the external agent responsible for changing the magnetic field with time.

Plus Two Physics Electro Magnetic Induction One Mark Questions and Answers

Question 1.
Eddy current are produced when.
(a) a metal is kept in varying magnetic field
(b) a metal is kept in steady magnetic field
(c) a circular coil is placed in a magnetic field
(d) through a circular coil, current is passed
Answer:
(a) a metal is kept in varying magnetic field

Question 2.
A100 milli henry coil carries a current of 1 A. energy stored in its magnetic field is
(a) 0.5 J
(b) 1 A
(c) 0.05 J
(d) 0.1 J
Answer:
(c) 0.05 J
Explanation : E = \(\frac{1}{2}\) LI² = \(\frac{1}{2}\) × (100 × 10^-3) × 1²
= 0.05 J.

Question 3.
A straight line conductor of length 0.4 m is moved with a speed of 7m/s perpendicular to a magnetic field of intensity 0.9 Wb/m². The induced e. m. f. across the conductor is.
(a) 5.04 V
(b) 25.2 V
(c) 1.26 V
(d) 2.52
Answer:
(d) 2.52
Induced e.m.f (s) = B/V
= 0.9 × 0.4 × 7 = 2.52V.

Question 4.
The core of a transformer is laminated because
(a) ratio of voltage in primary and secondary may be increased
(b) energy losses due to eddy currents may be minimized
(c) the weight of the transformer may be reduced
(d) rusting of the core may be prevented
Answer:
(b)

Plus Two Physics Electro Magnetic Induction Four Mark Questions and Answers

Question 1.

A conductor XY is moving through a uniform magnetic field of intensity B as shown in figure.

1. Name the emf.
2. The motion of XY towards right side causes an anticlockwise induced current. What will be the direction of magnetic induction in the region A?
3. The length of the conductor XY is 20cm. It is moving with a velocity 50m/s perpendicular to the magnetic fie Id. If the induced emf in the conductor is 2V find the magnitudes of magnetic field?

Answer:
1. Motional emf/induced emf.

2. Applying right hand grip rule at A direction of magnetic field is away from the paper.

3. ε = Blvsinθ, I = 20cm = 20 × 10^-2m, v
= 50m/s, ε = 2v

= 0.2 T.

Question 2.
1. When S₁ close bulb glows instantaneously when S₂ closes there is a delay in glowing the bulb.(1) This is due to………

• resistance of the coil
• back emf in the coil
• mutual induction
• none

2. Explain the phenomenon self-induction regarding above experiment (2)
3. Draw the graph with energy and current for a inductor. (1)
Answer:
1. Back emf in the coil.

2. When a.c. current is passed through the coil, a change in flux is produced. This change in flux produces a back e.m.f. in the coil. The phenomena of production of back emf is called self induction.

3. The graph with energy and current for a inductor:

Plus Two Physics Electro Magnetic Induction Five Mark Questions and Answers

Question 1.
When AC is switched on the thin metallic disc is found to thrown up in air.

1. Which makes the disc to thrown?
2. How will you explain the mechanism behind the movement of disc
3. Write the working principle of induction heater.

Answer:

1. Eddy current produced in the coil thrown disc into air.
2. Whenever the magnetic flux linked with a metal block changes, induced currents are produced due to this current, disc becomes a magnet. Hence disc thrown up in to air.
3. The change in flux produces eddy current in a metal. The heat produced by eddy current is used for cooking in induction heater.

Question 2.
AC generator is a device based on electromagnetic induction used to convert mechanical energy into electrical energy.

1. Draw a graph showing variation of induced emf over a cycle. Also indicate peak value of emf. (2)
2. How peak value of emf is related to its rms value? (1)
3. A rectangular wire loop of side 4cm × 6cm has 50 turns uniformly from 0.1 Tesla to 0.3 Tesla in 6 × 10^-2 second. Calculate induced emf in the coil. (2)

Answer:
1.

2. Erms = \(\frac{E_{0}}{\sqrt{2}}\)

3.

and Φ = BAN
Φ₁ = 0.1 × (24 × 10^-4) × 50
= 120 × 10^-4wb
Φ₂ = 0.3 × (24 × 10^-4) × 50
= 360 × 10^-4wb

= 40 × 10^-2V.

Students can Download Chapter 3 Production and Costs Questions and Answers, Plus Two Economics Chapter Wise Questions and Answers helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus Two Economics Chapter Wise Questions and Answers Chapter 3 Production and Costs

Plus Two Economics Production and Costs One Mark Questions and Answers

Question 1.
Which among the following cost curves is not ‘U’ shaped?
Answer:
AFC curve is rectangular hyperbola.

Question 2.
Identify the shape of the following AFC curve?
Answer:

The shape of AFC curve is rectangular hyperbola.

Question 3.
When a firm increased the number of labour from 10 to 11, keeping the capital fixed the total product increased from 120 to 130. Which of the following statement is correct in this regard?
(a) The total product fell
(b) This is a long run production
(c) The average product is rising
(d) 10 is the marginal product of an increased unit of labour.
Answer:
(d) 10 is the marginal product of an increased unit of labour.

Question 4.
Slope of an isoquant is:
(a) marginal cost
(b) DMRS
(c) DMRTS
(d) None of the above
Answer:
(c) DMRTS

Question 5.
When MP becomes zero, TP:
(a) increases
(b) decreases
(c) becomes maximum
(d) becomes negative
Answer:
(c) becomes maximum

Question 6.
Which among the following is not ‘u’ shape
(a) MC
(b) AC
(c) AVC
(d) AFC
Answer:
(d) AFC

Question 7.
When AC is minimum
(a) MC > AC
(b) MC = AC
(c) MC < AC
(d) None of these
Answer:
(b) MC = AC

Question 8.
All the following curves are U shaped except
(a) the AVC curve
(b) the AFC curve
(c) the AC curve
(d) the MC curve
Answer:
(b) the AFC curve

Plus Two Economics Production and Costs Two Mark Questions and Answers

Question 1.
Let the production function of a firm be Q = 5 L^1/2 K^1/2
Find the maximum output that the firm can produce with 100 units of L and 100 units of K.
Answer:
The production function is
Q = 5 L^1/2 K^1/2
Since the firm uses 100 units of L and 100 units of
K, we get the production function as
Q = 5 × 100^1/2 100^1/2
Q = 5 × 10x 10
Q = 5 × 100 = 500

Question 2.
Derive marginal product and average product from the total product schedule.

Answer:

Question 3.
Find the maximum possible output for a firm with zero units of labour and 10 units of capital when its production function is
Q = 5L + 2K
Answer:
The production function is Giving the values of L and K, we get
Q = 5 × 0 + 2 × 10
Q = 0 + 20 = 20

Question 4.
“In the long run, all costs are variable”. Do you agree? Justify your answer.
Answer:
Yes. In the long run, all costs are variable. This is because there is sufficient time available in the long run for any factor of production to get increased. As there are only variable factors, in the long run, all costs are variable.

Question 5.
“The AVC is U shaped” explain the reasons for the ‘U’ shape of AVC curve. Also, draw a diagram to clarify your points.
Answer:
The SMC and AVC curves start rising when production starts. As output increases, SMC falls. AVC being the average of marginal costs also falls but falls less than SMC. Then after a point, SMC start rising. AVC, however, continues to fall as long as value of SMC remains less than the prevailing value of AVC.

Once the SMC has risen sufficiently its value becomes greater than the value of AVC. The AVC starts rising. Therefore, the AVC curve is “U” shaped. It is given in the following diagram.

Question 6.
TFC of a firm is ₹2,000 and TVC is ₹3,000. It produces 20 units. Calculate the AVC and AC of the firm.
Answer:
TC = TFC + TVC
AC = 5000/20 = 250
AVC = 3000/20 = 150

Question 7.
Can there be some fixed cost in the long run?
Answer:
No, there cannot be some fixed cost in the long run. This is because, in the long run all factors of production can be adjusted and variable.

Question 8.
Let the production function of a firm be Q = 10 L^1/2 K^1/2 Find out the maximum possible output that the firm can produce with 100 units of L and 100 units of K.
Answer:
The production function is,
Q = 10 L^1/2 K^1/2
L =100 units
K =100 units
∴ Q = 10 × 1001/2 × 1001/2
= 10 × (10²)^1/2 × (10²)^1/2
= 10 × 10 × 10
= 1,000 units

Question 9.
The table given below shows the total product schedule of labour. Determine the AP and MP of labour?

Answer:

Question 10.
Prove that AC is the sum of AFC and AVC.
Answer:

Question 11.
A bus company started its operation with two buses, four labourers. It has paid a one-time road tax. As the passengers increased the company arranged more tripes, with the help of additional labour and for using more fuels. Classify the costs incurred by the bus company into fixed and variable.
Answer:

Question 12.
Both short run and long run average and marginal cost curves are U-shaped. But reasons for the U-shape are not the same. Bring out the differences.
Answer:
Behaviour of output in the short run as explained by the law of variable proportions Behaviour of output in the long run as explained by the laws of returns to scale.

Plus Two Economics Production and Costs Three Mark Questions and Answers

Question 1.
Match the following.

Answer:

Question 2.
Categorize the following into fixed cost
(a) wages of temporary workers
(b) cost of raw materials
(c) salary of permanent staff
(d) cost of transportation
(e) cost of plant
Answer:

Fixed Cost	Variable Cost
Salary of permanent staff	Cost of raw materials
Cost.of acquiring land	Cost of transportation
Cost of plant	Wages of temporary workers

Question 3.
Identify the following curves.

Answer:

1. TC
2. TVC
3. TFC

Question 4.
Identify the shapes of the following cost curves.

1. AFC
2. AC
3. TFC
4. TVC
5. TC

Answer:

1. AFC – Rectangular hyperbola
2. AC – ‘U’shape
3. TFC – Straight line parallel to X axis
4. TVC – Inverse‘S’ shape
5. TC – Inverse‘S’ shape

Question 5.
There exists vertical distance between 1. TVC and TC and (b) TC and TFC. What does this distance indicate?

1. TVC and TC
2. TC and TFC

Answer:

1. The vertical distance between TVC and TC represents the Total Fixed Costs (TFC).
2. The vertical distance between TC and TFC represents the Total Variable Costs (TVC)

Question 6.
Complete the following table

Answer:

Question 7.
Name the following curves. ,

Answer:

Question 8.
What do you mean by an ‘isoquant’?
Answer:
An isoquant is the set of all possible combinations of the two inputs that yield the same maximum possible level of output. Each isoquant represents a particular level of output and is labelled with that amount of output. The shape of isoquant is drawn below.

Question 9.
With the help of a diagram show the relation between average exists and average variable cost.

Answer:
Both AC and AVC are U shaped. As the output increases the gap between AC and AVC narrows.

Question 10.
In the short run, Total Variable Cost is zero when output is zero. When output rises, Total Cost also rises. Draw a suitable diagram and explain the relationship between Total Fixed Cost, Total Variable Cost and Total Cost.
Answer:

Question 11.
“Average Fixed Cost (AFC) curve is a continuously falling curve.”

1. Substantiate this statement by giving the reasons.
2. Graphically represent the AFC curve

Answer:
1. TFC is constant & hence AFC falls
2.

Plus Two Economics Production and Costs Five Mark Questions and Answers

Question 1.
The marginal product and total product of an input are related’. Prove this statement.’
Answer:
The marginal product (MP) and total product (TP) of an input are related. The points of relationship are given below.

1. When MP increases, TP also increases
2. When MP is zero, TP becomes maximum
3. When MP becomes negative, TP turns negative

Question 2.
Differentiate between returns to a factor and returns to scale.
Answer:
Returns to a factor refers to the effects on output of changes in one input with all other inputs are hold constant. On the other hand, returns to scale refers to the effect on total output of charges in some constant rate in all the inputs simultaneously.

Question 3.
The marginal cost and average cost are related to each other. Prove this using diagram and a numerical example?
Answer:

Marginal cost are addition made to the total costs by the production of an additional unit of the commodity.
MC = TC_n – TC_n-1

Average lost is per unit cost of production which is obtained by dividing the total cost by number of units of output produced.
\(A C=\frac{T C}{Q}\)

Since AC is obtained by dividing TC by all units, MC is the addition to TC by producing an additional unit so MC brings a change in AC.

From above:

1. When MC is less than AC, then MC will fall
2. When MC is equal to AC, AC remains costant.
3. When MC is more than AC, AC rises

Question 4.
Which of the following represent the long run production function?
1. MC is less than AC, then MC will fall

• Law of variable proportion
• Returns to scale

2.  Explain what may happen when all inputs vary simultaneously?
Answer:
Returns to scale.
When all inputs are varied simultaneously the output may change in three ways.
1. Constant returns to scale:
It is when a proportional increase in inputs result in an increase in output by the same proportion.

2. Increasing returns to scale:
It is when a proportional increase in all inputs result in an increase in output by more than proportion.

3. Decreasing returns to scale:
It is when a proportional increase in all inputs result in an increase in output by less than proportion

Question 5.
State whether the statement are true or false.

1. TC never becomes zero.
2. AC is sum total of AFC and AVC.
3. When AC rises, AC and MC are equal
4. Real cost is the cost in money terms
5. TFC curve is U shaped

Answer:

1. True
2. True
3. False
4. False
5. False

Question 6.
The following table shows the total cost schedule of a firm. What is the total fixed cost schedule of the firm? Calculate the JVC, AFC, AVC, SAC and SMC of the firm

Answer:

Question 7.
The diagram shows the total product curve of a factor in the law of variable proportion.

1. Explain the law
2. With the help of a diagram illustrate the average and marginal product curve and their relation.

Answer:
1. Law of variable proportion says that if one variable input is added with other fixed inputs the marginal product of a factor input initially rises but after reaching a certain level of output it starts falling.

2. The relation between the average and marginal product is given below. BothAPand MPare ‘n ’shaped. MPwill always pass through the maximum of AP.

Question 8.
Theory of production deals with producer’s behaviour, and according to this theory output produced by a firm passes through three stages in the short run.

1. Which are the three stages of production?
2. Analyse and bring out the salient features of each stage.
3. Which stage of production is very important as far as a firm is concerned? Why?
4. Give suitable diagram by drawing the Total Prod-uct, Average Product & Marginal Product curves.

Answer:

1. Increasing, diminishing and negative
2. First output increases at increasing rate, then at diminishing rate & finally starts falling.
3. Second stage, profit maximisation occurs in this Stage.
4.

Question 9.
If other things remaining same, graphically explain what happens to the supply curve for readymade shirts if there is

1. An increase in the wages paid to the tailors.
2. An increase in the price of ready-made shirts

Answer:

Plus Two Economics Production and Costs Eight Mark Questions and Answers

Question 1.
Prepare a seminar report on the topic “Production Function.”
Answer:
Respected teachers and dear friends:
The topic of my seminar paper is “Production Function”. The production function of a firm shows relationship between inputs and output. In this seminar paper, I would like to present the different production functions such as short run production function and the long run production function.

Introduction:
As we know the production function shows the transformation of inputs into output. The production function can be of two types – short run production function known as Law of Variable proportion and the long run production function known as returns to scale. Q =F(F₁ F₂… F_n)

Contents:
A. Law of Variable proportion

1. Increasing returns
2. Diminishing returns
3. Negative returns

A. The Law of Variable Proportions
When more and more units of a variable input are added with the fixed input, the marginal product would increase only upto a certain point. Therefore, the marginal product declines. This phenomenon is known as the Law of Variable Proportions. It is also known as returns to a factor.

The shape of TP, AP and MP suggests that they are specifically passing through three phases.
They are:
1. First phase:
In the first stage, both AP and MP increase. As a result TP also increases at an increasing rate. This stage is known as the stage of increasing return to a factor. AP reaches the maximum level in this stage.

2. Second phase:
Both AP and MP decrease at this stage. The TP increases at a decreasing rate. More importantly, TP reaches maximum and MP touches zero. This stage is also known as the stage of diminishing returns to a factor.

3. Third phase:
At this stage, the MP becomes negative. As a result, TP also starts declining. The decline of AP is continuous. In the graph, when TP reaches maximum and MP touches zero. When MP becomes negative, TP starts declining. This stage is known as the stage of negative returns to a factor.

B. Returns to scale

1. Increasing returns
2. Constant returns
3. Decreasing returns
   (for details, refer summary part)

B. Returns to scale
As stated earlier, all the factor inputs become variable in the long run and thereby no distinction can be made between fixed inputs and variable inputs. Return to scale is associated with long run production function.

Returns to scale refers to the change in output when all inputs are variable and the proportion between inputs remains constant. When all the inputs vary in the same proportion, the output (TP) behaves in different manner, which can be clubbed into three categories.

1. Increasing Returns to Scale (IRS):
When a proportionate change in all the inputs leads to more than proportionate change in output, it is known as the stage of increasing returns to scale. For instance, a 10% change in inputs results in more than 10% change in output.

2. Constant Returns to Scale (CRS):
When a proportionate change in all the inputs leads to change in output in the same proportion is known as the stage of constant returns to scale. It indicates that a 10% change in inputs leads to exactly 10% change in output.

3. Decreasing Returns to Scale (DRS):
When a proportionate change in all the inputs leads to less than proportionate change in output is known as the stage of decreasing returns to scale. It indicates that a 10% change in inputs leads to less than 10% change in output.

Conclusion:
Thus it can be concluded that there are two types of production function depending upon the use of inputs and the time period.

Question 2.
Prepare a seminar paper on Law of Returns to Scale.
Answer:
Returns to scale:
As stated earlier, all the factor inputs become variable in the long run and thereby no distinction can be made between fixed inputs and variable inputs. Return to scale is associated with long run production function.

Returns to scale refers to the change in output when all inputs are variable and the proportion between inputs remains constant. When all the inputs vary in the same proportion, the output (TP) behaves in different manner, which can be clubbed into three categories.

1. Increasing Returns to Scale (IRS):
When a proportionate change in all the inputs leads to more than proportionate change in output, it is known as the stage of increasing returns to scale. For instance, a 10 percentage change in inputs results in more than 10 percentage change in output.

2. Constant Returns to Scale (CRS):
When a proportionate change in all the inputs leads to change in output in the same proportion is known as the stage of constant returns to scale. It indicates that a 10 percentage change in inputs leads to exactly 10 percentage change in output.

3. Decreasing Returns to Scale (DRS):
When a proportionate change in all the inputs leads to less than proportionate change in output is known as the stage of decreasing returns to scale. It indicates that a 10 percentage change in inputs leads to less than 10 percentage change in output.

Question 3.
From the table given below

1. Fill the blank columns
2. Using the information in the table draw TC, TVC, TFC in one and AC, AVC, AFC, MC in other and prepare a short note on them.

Answer:
1.

2. Use the data to draw the diagram.
TC, TVC and TFC represent total costs. TC = TFC + TVC. TFC is the cost incurred on fixed factors. TVC is the cost incurred on variable costs. Even though the level of output is zero there will be some costs. This is known as fixed cost. When the level of output is zero total variable costs also will be zero.

It will increase as the level of output increases. AFC is the cost that always falls. It is a rectangular hyperbola. AVC, AC, MC are ‘U’ shaped. The MC will always pass through the minimum oftheAVCand AC.

Students can Download Chapter 12 Aldehydes, Ketones and Carboxylic Acids Questions and Answers, Plus Two Chemistry Chapter Wise Questions and Answers helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus Two Chemistry Chapter Wise Questions and Answers Chapter 12 Aldehydes, Ketones and Carboxylic Acids

Plus Two Chemistry Aldehydes, Ketones and Carboxylic Acids One Mark Questions and Answers

Question 1.
The reaction is called
(a) Sandmeyer’s reaction
(b) Rosenmund’s reduction
(c) HVZ reaction
(d) Cannizaro’s reaction
Answer:
(b) Rosenmund’s reduction

Question 2.
Say TRUE or FALSE:
Aldol condensation is given by all aldehydes and ketones.
Answer:
False

Question 3.
A 40% solution of _________ is called formation
Answer:
formaldehyde (HCHO)

Question 4.
Benzamide on heating with bromine and caustic alkali gives
(a) benzene
(b) methylamine and benzene
(c) aniline
(d) m-Bromobenzaldehyde
Answer:
(c) aniline

Question 5.
In the reaction the product ‘B’ is
(a) acetanilide
(b) glycine
(c) ammonium acetate
(d) methane
Answer:
(b) glycine

Question 6.
Arrange the following in the decreasing order of acidity.
ClCH₂COOH, Cl₃CCOOH, CH₃COOH, Cl₂HCOOH
Answer:
Cl₃CCOOH > Cl₂CHCOOH > ClCH₂COOH > CH₃COOH

Question 7.
Reaction of butanone with methyl magnesium bromiode followed by hydrolysis gives_________
Answer:
2 methyl -2- butanol

Question 8.
The major product of the addition of water molecule to propyne in the presence of mercuric sulphate and dil sulphuric acid is ________
Answer:
Propanone

Question 9.
One mole of propanone and one mole of formalde¬hyde are the products of ozonolysis of one mole of an alkene. The alkene is ________
Answer:
2 methyl propene

Question 10.
Which of the following is a better reducing agent for the following reduction.
RCOOH → RCH₂OH
(a) SnCI₂/HCI
(b) NaBH₄/ether
(c) H₂/pd
(d) N₂H₄/C₂H₅ONa
(e) B₂H₆/H₃O⁺
Answer:
(e) B₂H₆/H₃O⁺

Question 11.
The total number of acyclic structural isomers possible for compound with molecular formula C₄H₁₀O is ________
Answer:
7

Plus Two Chemistry Aldehydes, Ketones and Carboxylic Acids Two Mark Questions and Answers

Question 1.
Reactivity of ketone is less than that of aldehyde. Why?
Answer:
Due to steric hindrance and inductive effect of alkyl group.

Question 2.
Carboxylic acid decompose into carboxylate ion and H⁺ ion.

1. Explain this on the basis of resonating structure of carboxylic acid.
2. Arrange the following in the increasing order of acidity. HCOOH, CH₃COOH
3. Substantiate.

Answer:

1. Carboxylic acid decomposes to give proton and carboxylate ion and is stabilized by resonance. This explains the acidic character of carboxylic acid.
2. CH₃COOH < HCOOH
3. In acetic acid the electron donating effect (+l – effect) of -CH₃ group destabilises the carboxylate anion and decreases the acid strength. Whereas in formic acid the H atom has not electron withdrawing or electron donating effect.

Question 3.
What is Etard’s reaction?
Answer:
Etard’s reaction:
When toluene is oxidized using chromyl chloride, benzaldehyde is obtained.

Question 4.
What is HVZ reaction? Explain.
Answer:
HVZ reaction – When a carboxylic acid is treated with red P and halogen, the α-H atoms are successively replaced by halogen.

This reaction has great synthetic importance as the halogen atom can be replaced by a number of other groups giving useful products.

Question 5.
Predict the product and name the reaction:

1. HCHO + NaOH → B + C
2. CH₃COOH + CH₃OH → E

Answer:

1. CH₃OH + HCOONa – Cannizzaro reaction
2. CH₃COOCH₃ – Esterification

Question 6.
Write the name of any two tests to distinguish between acetaldehyde and acetone.
Answer:
Benedict’s test, Fehling’s test – Both tests are answered by acetaldehyde and not by aceotne.

Question 7.
An organic compound with molecular formula C₉H₁₀O forms 2, 4-DNP derivative, reduces Tollens’reagent and undergoes Cannizzaro reaction. On vigorous oxidation, it gives 1, 2-benzenedicarboxylic acid. Identify the compound.
Answer:
From the given data it is clear that as the compound forms2, 4-DNP derivative it has /CO group. Since it reduces Tollens’ reagent therefore -CHO group is present. As it can also undergo Cannizzaro reaction therefore α -hydrogen is absent

The oxidation product suggests that the compound has a benzene ring. One of the – COOH groups have been obtained by the oxidation of – CHO group and the other from alkyl group. Hence on these basis, the structure of C₉H₁₀O is

Question 8.
Write a notes on

1. Reimer – Tiemann reaction
2. Rosenmund Reduction

Answer:
1. Reimer – Tiemman reaction: When phenol is heated with CHCI₃ at 340 K, o-hydroxy benzaldehyde or salicylaldehyde is obtained.

2. Rosenmund reduction: When an acid chloride is reduced by using hydrogen gas in presence of Pd and BaSO₄, an aldehyde is obtained.
OR

Question 9.
Distinguish the following compounds using any one test.
H₃C – CO – CH₃ and CH₃CH₂CHO
Answer:
CH₃COCH₃ give Iodoform test which CH₃CHO does not answer this test.

Question 10.
Aspirin is commonly used in medicine. How it is prepared? Give the equation.
Answer:
Aspirin is acetyl salicyclic acid. When salicyclic acid is treated with acetyl chloride, aspirin is obtained.

Salicylic acid + acetyl chloride → Aspirin

Question 11.
How will you prepare CH₃-CO-NH₂ and CH₃COOCH₃ from CH3COOH?
Answer:

Question 12.
Give the IUPAC name of the following compounds.
i) C₆H₅CH = CHCHO
ii) (CH₃)₃CCH₂COOH
Answer:

Question 13.
Give a test to distinguish between acetaldehyde and acetone.
Answer:
CH₃ – CO – CH₃ contains CH₃CO – group and hence it gives iodoform test.
CH₃ – CH₂ – CHO does not give iodoform test.

Question 14.
Predict the major product in the following reactions:

Answer:

Question 15.
Distinguish between formaldehyde & acetaldehyde.
Answer:

HCHO	CH3CHO
1. It gives Cannizzaro reaction.	1. It doesn’t give Cannizzaro reaction.
2. It doesn’t give aldol condensation.	2. It gives aldol condensation.
3. It gives condensation products with NH3.	3. It gives addition products with NH3.

Question 16.
Which is more acidic, 2-chloropropanoic acid or 3- chloropropanoicacid? Why?
Answer:
2-chloropropanoic acid. Becasue the electron with drawing -Cl group is more closer to -COOH group in this compound.

Plus Two Chemistry Aldehydes, Ketones and Carboxylic Acids Three Mark Questions and Answers

Question 1.
Fill in the blanks:

Answer:

Question 2.
A student is given Tollens’ reagent for oxidation of aldehyde.

1. What is Tollens’ reagent?
2. Can you help him to do the experiment?
3. What is the result of the experiment?

Answer:

1. Tollens’ reagent is ammoniacal silver nitrate solution
2. Yes. To a little of the solution add Tollens’ reagent
3. A black precipitate of silver or silver mirror is obtained

Question 3.

1. What is the role of LiAIH₄?
2. Give one example of an oxidising agent?
3. What is the action of a carboxylic acid with alcohol?

Answer:

1. LiAIH₄ is a strong reducing agent. It reduces RCOOH to 1° alcohol (RCH₂OH)
2. Acidified KMnO₄.
3. When carboxylic acid is treated with an alcohol in the presence of dehydrating agent like conc.H₂SO₄, an ester is formed. This is called esterification reaction.

Question 4.
What happens when primary, secondary and tertiary alcohols are passed over red hot copper? Give equations.
Answer:
1° alcohol hot copper Aldehyde
2° alcohol over hot copper – Ketone
3° alcohol over hot copper- alkene

Question 5
Fill in the blanks.

Answer:

1. HVZ reaction
2. CH₃CH₃
3. Hoffmann bromamide degradation reaction
4. HCOONa + CH₃OH
5. Reimer-Tiemann reaction
6. C₆H₅Cl

Question 6.
Draw the structure of the following derivatives.
(i) The 2,4-dinitrophenylhydrazone of benzaldehyde
(ii) Cyclopropanone oxime
(iii) Acetaldehydedimethylacetal
(iv) The semicarbazone of cyclobutanone
(v) The ethylene ketal of hexan-3-one
(vi) The methyl hemiacetal of formaldehyde
Answer:

Question 7.

i) 2HCHO + NaOH → CH₃OH + HCOONa
ii)

(a) Identify Cannizzaro and Aldol condensation.
(b) What is the difference between the above two reactions?

Answer:
(a) Cannizzaro reaction:
2HCHO + NaOH CH₃OH + HCOONa
Aldol condensation:

(b) Cannizzaro reaction is given by aldehydes having no α-H atom whereas aldol condensation is given by aldehydes containing α-H atom.

Question 8.
a) In a practical class a group of students heated ethanal with NaOH. Another group heated methanal with conc.NaOH.
i) Identify the products in each reaction with equation.
ii) Name the reactions.
b) Aldehydes are more reactive than ketones. Comment on the statement.
Answer:
a)

ii) The first reaction is Cannizarro reaction and the second reaction is aldol condensation.

b) Due to the ‘+l’ effect and steric hindrance of surrounding alkyl group ketones are less reactive than aldehydes.

Plus Two Chemistry Aldehydes, Ketones and Carboxylic Acids Four Mark Questions and Answers

Question 1.
i) Arrange the following in the increasing order of acidic strength and justify your answer.
CH₃COOH, CHCI₂COOH, CH₂CICOOH, CCI₃COOH

ii) Suggest a method to convert acetic acid to chloroacetic acid. Name the reaction and write the chemical equation.
Answer:
i) CH₃COOH < CH₂CI-COOH < CHCI₂COOH < CCI₃COOH This is due to the electron withdrawing character of chlorine.

ii) HVZ reaction – When a carboxylic acid is treated with red P and halogen, the a-H atoms are successively replaced by halogen.

This reaction has great synthetic importance as the halogen atom can be replaced by a number of other groups giving useful products.

Question 2.
a) Which of the following carbonyl compounds answer aldol condensation reaction and give equation.
HCHO, CH₃CHO, CCI₃CHO, C₆H₆-CHO

b) Arrange the following compounds in the increasing order of acidity:
CH₃COOH, CH₂CICOOH, CH₃-CH₂-COOH, C₆H₅-COOH
Answer:
a) Among these compounds only CH₃CHO answer aldol condensation reaction. Others will not answer this reaction because they have no α – hydrogen atom.

Question 3.

1. Aldehydes and ketones are carbonyl compounds Give a test for identification of aldehydes.
2. Acidic strength is related to the stability of carboxylate anion. Which acid of each pair is stronger?

Answer:
1. Benedict test. Benedict reagent is a mixture of sodium carbonate and sodium citrate. This on reaction with aldehyde gives red precipitate of Cu₂S.

2. Acidic strength is related to the stability of carboxylate anion. Acid of each pair is stronger:
i) CH₂FCOOH. This is due to the high electron with drawing effect of F.

This is due to the high electron with drawing effect of the -CF₃ group.

Question 4.
Substituents on carboxylic acids have much effect on their acidity. Substantiate the statement with the following examples.
a) HCOOH, CH₃COOH, CH₂CICOOH

Answer:
CH₂CICOOH > HCOOH > CH₃COOH
The methyl group will intensify the negative charge on the carboxylate ion and destabilise it as compared to formate ion. So HCOOH is stronger than CH₃COOH. The electron withdrawing effect of a Cl makes chloroacetic acid stronger than HCOOH and CH₃COOH.

In the case of aromatic carboxylic acids, presence of electron withdrawing groups at ortho and para position increases their acidity while presence of electron donating groups decreases their acidity.

In 4-nitro benzonic acid acid strength is greater than that of benzoic acid due to the electron withdrawing nature of -NO₂ group while in 4-methoxy benzoic acid acid strength decreases due to the electron donating nature of the methoxy group.

Question 5.
Give a chemical test to distinguish between each of
the following pair of organic compounds.

1. Propanal and Propanol
2. Propanone and Propanal

Answer:

1. Propanal is an aldehyde and it gives a silver mirror with Tollens’ reagent while propanol is an alcohol and will not answer Tollens’test.

2. Propanone gives yellow precipitate of iodoform on reaction with I₂ and NaOH while propanal does not give iodoform test. OR Propanal gives silver mirror with Tollens’ reagent while propanone does not give silver mirror test.

Question 6.
What is meant by the following terms? Give an example of the reaction in each case.

1. Cyanohydrin
2. Acetal
3. Semicarbazone
4. Aldol
5. Hemiacetal
6. Oxime
7. Ketal
8. Imine
9. 2,4-DNP-derivative
10. Schiff’s base

Answer:
1. Cyanohydrin – It is a compound which contain both OH and CN groups. For example, Lactic acid can be obtained by hydrolysis of cyanohydrin.

2. Acetal – compounds formed by the reaction of aldehydes with monohydric alcohols in presence of dry HCI gas.

3. Semicarbazone – the product of carbonyl compounds with semicarbazide is known as semicarbazone.

4. Aldol – It is a condensation product of aldehydes or ketones having atleast one α – hydrogen atom with dilute alkali as catalyst.

5. Hemiacetal – It is a compound which contains an ether as well as alcohol functional group. For example, methoxyethanol is a hemiacetal.

6. Oxime – Addition compound formed by the reaction of aldehyde or ketone with hydroxylamine.

7. Ketal – It is a cyclic compound obtained by reaction of aceone with ethylene glycol.

8. Imine – Addition compound formed by the reaction of aldehyde or ketone with ammonia.

9. 2, 4-DNP derivative – 2, 4-phenylhydrazone (DNP) is the addition compound formed by the reaction of aldehydes and ketones with 2, 4-dinitrophenylhydrazine.

10. Schiff’s base – Addition compound formed by the reaction of aldehyde or ketone with amine.

Question 7.
Name the following compounds according to IUPAC system of nomenclature.

1. CH₃CH(CH₃)CH₂CH₂CHO
2. CH₃CH₂COCH(C₂H₅)CH₂CH₂CI
3. CH₃CH=CHCHO
4. CH₃COCH₂COCH₃
5. CH₃CH(CH₃)CH₂C(CH₃)₂COCH₃
6. (CH₃)₂CCH₂COOH
7. OHCC₆H₅CHO-p

Answer:

1. 4-Methylpentanal
2. 6-Chloro-4-ethylhexan-3-one
3. But-2-enal
4. Pentane-2,4-dione
5. 3, 3, 5-Trimethylhexane-3-one
6. 3, 3-Dimethylbutanoicacid
7. Benzene 1, 4-dicarbaldehyde

Question 8.

1. What is the relation between an electron donating group and acidic character?
2. How carboxylic acids maintain their acid character?

Answer:

1. Electron donating group decreases the acid character.
2. Carboxylic acid decomposes to give proton and carboxylate ion and is stabilized by resonance. This explains the acidic character of carboxylic acid.

Question 9.
Predict the product formed when cyclohexane carbaldehyde reacts with following reagents:
i) PhMgBr and then H₃O⁺
ii) Tollens’reagent
iii) Semicarbazide and weak acid
iv) Excess ethanol and acid
v) Zinc amalgam and dilute hydrochloric acid
Answer:

Plus Two Chemistry Aldehydes, Ketones and Carboxylic Acids NCERT Questions and Answers

Question 1.
What is meant by the following terms? Give an example of the reaction in each case

1. Cyanohydrin
2. Acetal
3. Semicarbazone
4. Aldol
5. Hemiacetal
6. Oxime
7. Ketal
8. Imine
9. 2,4-DNP-derivative
10. Schiff’s base

Answer:
1. Cyanohydrin – It is a compound which contain both OH and CN groups. For example, Lactic acid can be obtained by hydrolysis of cyanohydrin.

2. Acetal – compounds formed by the reaction of aldehydes with monohydric alcohols in presence of dry HCI gas.

3. Semicarbazone – the product of carbonyl compounds with semicarbazide is known as semicarbazone.

4. Aldol – It is a condensation product of aldehydes or ketones having atleast one α – hydrogen atom with dilute alkali as catalyst.

5. Hemiacetal – It is a compound which contains an ether as well as alcohol functional group. For example, methoxyethanol is a hemiacetal.

6. Oxime – Addition compound formed by the reaction of aldehyde or ketone with hydroxylamine.

7. Ketal – It is a cyclic compound obtained by reaction of aceone with ethylene glycol.

8. Imine – Addition compound formed by the reaction of aldehyde or ketone with ammonia.

9. 2, 4-DNP derivative – 2, 4-phenylhydrazone (DNP) is the addition compound formed by the reaction of aldehydes and ketones with 2, 4-dinitrophenylhydrazine.

10. Schiff’s base – Addition compound formed by the reaction of aldehyde or ketone with amine.

Question 2.
Name the following compounds according to IUPAC system of nomenclature.

1. CH₃CH(CH₃)CH₂CH₂CHO
2. CH₃CH₂COCH(C₂H₅)CH₂CH₂CI
3. CH₃CH = CHCHO
4. CH₃COCH₂COCH₃
5. CH₃CH(CH₃)CH₂C(CH₃)₂COCH₃
6. (CH₃)₃CCH₂COOH
7. OHCC₆H₅CHO-p

Answer:

1. 4-Methylpentanal
2. 6-Chloro-4-ethylhexan-3-one
3. But-2-enal
4. Pentane-2,4-dione
5. 3, 3, 5-Trimethylhexane-3-one
6. 3, 3-Dimethylbutanoicacid
7. Benzene 1, 4-dicarbaldehyde

Question 3.
Draw the structure of the following compounds
(i) 3-Methylbutanal
(ii) p-Nitropropiophenone
(iii) p-methylbenzaldehyde
(iv) 4-methylpent-3-en-2-one
(v) 3-bromo-4-phenylpentanoicacid
(vi) 4-Chloropentan-2-one
(vii) p, p-Dihydroxybenzophenone
(viii) Hex-2-en-4-ynoicacid
Answer:

Question 4.
An organic compound with molecular formula C₉H₁₀O forms 2, 4-DNP derivative, reduces Tollens’reagent and undergoes Cannizzaro reaction. On vigorous oxidation, it gives 1, 2-benzene dicarboxylic acid. Identify the compound.
Answer:
From the given data it is clear that as the compound forms 2, 4-DNP derivative it has >CO group. Since it reduces Tollens’ reagent -CHO group is present. As it can also undergo Cannizzaro reaction α- hydrogen is absent.

The oxidation product suggests that the compound has a benzene ring. One of the – COOH groups have been obtained by the oxidation of – CHO group and the other from alkyl group. Hence on these basis, the structure of C₉H₁₀O is

Question 5.
Write structural formulas and names of the four possible aldol condensation products from propanal and butanal. In each case, indicate which aldehyde served as nucleophile and which as electrophile.
Answer:
i) Propanal as electrophile as well as nucleophile

ii) Propanal as electrophile and butanal as nucleophile

iii) Butanal as electrophile and propanal as nucleophile

iv) Butanal as electrophile as well as nucleophile

Question 6.
Predict the product formed when cyclohexane carbaldehyde reacts with following reagents:
i) PhMgBr and then H₃O⁺
ii) Tollens’reagent
iii) Semicarbazide and weak acid
iv) Excess ethanol and acid
v) Zinc amalgam and dilute hydrochloric acid
Answer:

Question 7.
Give simple chemical tests to distinguish between

1. Propanal and propanone
2. Acetophenone and Benzophenone
3. Phenol and Benzoic acid
4. Benzaldehyde and acetophenone
5. Ethanal and propanal

Answer:
1. Propanal and propanone:
Propanal and propanone can be distinguished by iodoform test as it is given by propanone and not by propanal
Propanone reacts with hot NaOH/I₂ to give yellow precipitate of iodoform.

2. Acetophenone and benzophenone:
Acetophenone gives iodoform test but benzophenone does not respond.

3. Phenol and benzoic acid:
This can be distinguished by treating FeCI₃ solution. Phenol gives violet colour with FeCI₃ solution while benzoic acid gives buff colured precipitate.

4. Benzaldehyde and acetophenone:
Acetophenone responds to iodoform test while benzaldehyde does not.

5. Ethanal and propanal:
Ethanal gives yellow ppt. of iodoform with an alkaline solution of iodine (iodoform test)

Propanal does not give yellow ppt.

Students can Download Chapter 5 Magnetism and Matter Questions and Answers, Plus Two Physics Chapter Wise Questions and Answers helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus Two Physics Chapter Wise Questions and Answers Chapter 5 Magnetism and Matter

Plus Two Physics Magnetism and Matter NCERT Text Book Questions and Answers

Question 1.
Answer the following questions regarding earth’s magnetism:

1. A vector needs three quantities for its specification. Name the three independent quantities conventionally used to specify the earth’s magnetic field.
2. The angle of dip at a location in southern India is about 18°. Would you expect a greater or lesser dip angle in Britain?
3. If you make a map of magnetic field lines at Melbourne in Australia, would the lines seen to go into the ground or come out of the ground?
4. In which direction would a compass free to move in the vertical plane point to, if located right on the geomagnetic north or south pole?
5. The earth’s field is claimed roughly approximately, the field due to a dipole magnetic moment 8 × 10²² JT^-1 located at the centre. Check your or¬der of magnitude of this number same way.
6. Geologists claim that besides the main magnetic NS poles, there are several local poles on the earth’s surface oriented in different directions. How is such a thing possible at all?

Answer:
1. Magnetic declination, angle of dip, horizontal component of earth’s magnetic field.

2. Greater angle of dip in Britain, (it is about 70°), because Britain is closer to the magnetic north pole.

3. Field lines of B due to the earth’s magnetism would seem to come out of the ground.

4. A compass is free to move in a horizontal plane, while the earth’s field is exactly vertical at the magnetic poles. So the compass can point in any direction there.

5. Use the formula for field B on the normal bisector of a dipole of magnetic moment m.
B = \(\frac{\mu_{0}}{4 \pi} \frac{M}{r^{3}}\)
Take M = 8 × 10²² JT^-1
r = 6.4 × 10⁶ m;
one gets B = 0.3G
which checks with the orde of magnitude of the observed field on the earth.

6. The earth’s field is only approximately a dipole field. Local N-S poles may arise due to, for instance, magnetized minerals deposits.

Question 2.
A short bar magnet of magnetic moment m = 0.32JT^-1 is placed in a uniform external magnetic field of 0.15T. If the bar is free to rotate in the plane of the field, which orientations would correspond to its

• stable and
• unstable equilibrium? What is the potential energy of the magnet in each case?

Answer:
Given M=0.32JT^-1 B = 0.15T, U = ?

• If \(\overrightarrow{\mathrm{M}} \| \overrightarrow{\mathrm{B}}\), then we have stable equilibrium and U = -MB = -0.32 × 0.15T = -4.8 × 10^-2 J
• If \(\overrightarrow{\mathrm{M}}\) is anti-parallel to \(\overrightarrow{\mathrm{B}}\) , we have unstable equilibrium and
  U = MB = 0.32 × 0.15J = 4.8 × 10^-2J

Question 3.
A closely wound solenoid of 800 turns and area of cross-section 2.5 × 10^-4 m² carries a current of 3.0A. Explain the sense in which the solenoid acts like a bar magnet. What is its associated magnetic moment?
Answer:
Given N = 800, A = 2.5 × 10^-4 m², I = 3.0A, M = ?
Since M = NIA
∴ M = 800 × 3 × 2.5 × 10^-4
or M = 0.60JT^-1 along the axis of the solenoid.

Question 4.
A closely wound solenoid of 2000 turns and area of cross-section 1.6 × 10^-4 m², carrying a current of 4.0A, is suspended through its centre allowing it to turn in a horizontal plane.

1. What is the magnetic moment associated with the solenoid?
2. What is the force and torque on the solenoid if a uniform horizontal magnetic field of 7.5 × 10^-2 is set up at an angle of 30° with the axis of the sole¬noid?

Answer:
1. Magnetic dipole moment,
M = nIA
= 2000 × 4.0 × 1.6 × 10^-4 = 1.28JT^-1

2. Net force = 0
Torque, τ = MB sinθ
= 1.28 × 7.5 × 10^-2 × sin 30°
= 1.28 × 7.5 × 10^-3 × 1/2 = 4.8 × 10^-2 Nm.

Question 5.
Answer the following questions:

1. Why does a paramagnetic sample display greater magnetization (for the same magnetizing field) when cooled?
2. Why is diamagnetism, in contrast, almost independent of temperature?
3. If a toroid used bismuth for its core, will the field in the core be (slightly) greater or (slightly) less than when the core is empty?
4.  If the permeability of a ferromagnetic material independent of the magnetic field? If not is it more for lower or higher fields?
5. Magnetic field lines are always nearly normal to the surface of a ferromagnet at every point.
6. Would the maximum possible magnetisation of a paramagnetic sample be of the same order of magnitude as the magnetisation of a ferromagnet?

Answer:
1. The tendency to disrupt the alignment of dipoles (with the magnetising field) arising from random thermal motion is reduced at lower temperatures.

2. The induced dipole moment in a diamagnetic sample is always opposite to the magnetising field, no matter what the internal motion of the atom is.

3. Slightly less, since bismuth is diamagnetic.

4. No, as is evident from the magnetisation curve. From the slope of the magnetisation curve, it is clear that μ is greater for lower fields.

5. Proof of the important fact (of much practical use) is based on boundary conditions of magnetic fields (B & H) at the interface of two media. (When one of the media has μ>>1, the field lines meet this medium nearly normally).

6. Yes. Apart from minor differences in the strength of the individual atomic dipoles of two different materials, a paramagnetic sample with saturated magnetisation will have the same order of magnetisation. But of course, saturation requires impractically high magnetising fields.

Plus Two Physics Magnetism and Matter One Mark Questions and Answers

Question 1.
Nickel shows ferromagnetic property at room temperature. If the temperature is increased beyond Curie temperature, then it will show
(a) anti ferromagnetism
(b) no magnetic property
(c) diamagnetism
(d) paramagnetism
Answer:
(d) paramagnetism

Question 2.
According to Curie’s law, the magnetic susceptibility of a substance at an absolute temperature T is proportional to
(a) 1/T
(b) T
(c) 1/T²
(d) T²
Answer:
(a) 1/T
Explanation : According to Curie’s law X ∝ \(\frac{1}{T}\)

Question 3.
Above Curie temperature
(a) a paramagnetic substance becomes ferromagnetic substance
(b) a ferromagnetic substance becomes paramagnetic
(c) a paramagnetic substance becomes diamagnetic
(d) a diamagnetic substance becomes paramagnetic
Answer:
(b) a ferromagnetic substance becomes paramagnetic

Plus Two Physics Magnetism and Matter Two Mark Questions and Answers

Question 1.
Classify the following properties into diamagnetic, paramagnetic and ferromagnetic.

1. Susceptibility -1≤x<0
2. In uniform magnetic field it acquires a large magnetisation in the direction of the field.
3. When it is suspended in a magnetic field, it will come to rest perpendiculartothe magnetic field.
4. Susceptibility of the substance varies inversely as temperature of the substance upto curie temperature ie. x_m∝ \(\frac{1}{T}\)

Answer:

• Dia – a,c
• Para – d
• Ferro – b

Question 2.
Classify the following properties into diamagnetism and ferro magnetism.

1. In non uniform magnetic field, it more from high to law field.
2. Magnetic field lines are repelled from this material, If we place in a external magnetic field.
3. susceptibility greater than one, <0, +ve
4. Iron, Nickel, Cobalt are the examples

Answer:

1. Diamagnetism
2. Diamagnetism
3. Ferro magnetism
4. Ferro magnetism

Question 3.
Fill in the blanks.

Answer:

1. negative
2. Weak magnetic field to strong magnetic field.
3. Individual atoms have tiny magnetic moments
4. µ_r >1

Plus Two Physics Magnetism and Matter Three Mark Questions and Answers

Question 1.
The figure shows hysteresis curves for soft iron and stell.

1. Which among the two is the hysteresis loop of soft iron?
2. Which one among the two materials is preferred for use in transformers and galvanometers?
3. When steel is once magnetized, the magnetiza-tion is not easily destroyed even if it is exposed to strong reverse fields. Give reason.

Answer:

1. Fig. b
2. Soft iron
3. When steel is magnetised the magnetic domains in the material is permanently set and magnetised permanently in the direction of the applied magnetic field.

Question 2.
The figure shows a liquid placed on the pole pieces of two magnets.

1. Which magnetic behaviour is exhibited by the liquid? (1)
2. Write any two characteristics of this magnetic behaviour? (1)
3. Does this behaviour transform with temperature. Why? (1)

Answer:
1. Diamagnetism
2. characteristics of this magnetic behaviour:

• Permeability of a diamagnetic material is less than one.
• Susceptibility is small and negative.

3. No. The magnetic dipole moment induced in the diamagnetic material is opposite to the magnetising field and hence does not affect the thermal motion of atoms. Hence change in temperature has no effect on diamagnetism.

Question 3.
A magnetic material contained in a curved glass plate, when placed in a nonuniform magnetic field, exhibits a property as shown in figure.

1. Which type of magnetic material is this? Explain the property
2. Write two examples for such a magnetic material. Explain how the property relates with temperature?
3. “The susceptibility of a material is small” what do you mean by this statement.

Answer:

1. Diamagnetism: Diamagnetic materials are repelled from external magnetic field.
2. Bismuth, Copper, Lead, Nitrogen, Water. Diamagnetism is independent of temperature.
3. Diamagnetism developed by external magnetic field is very small.

Question 4.
A place where dip = 90°, B_H = 0

1. This place is at…………
2. What is the value of B_u at this place?
3. Can a magnetic needle align in the N-S direction at this place?

Answer:
1. Magnetic pole.

2. B = \(\sqrt{B_{v}^{2}+B_{h}^{2}}\)
But B_h = 0
∴ B = B_v

3. No. Magnetic needle align vertically

Question 5.
Classify into diamagnet, Paramagnet and Fero magnet.

1. Feebly magnetized in the same direction
2. m_r slightly more than none
3. does not allow lines of force
4. temperature independent
5. exhibit hysteresis
6. strongly attracted by a bar magnet

Answer:

1. Paramagnet
2. Para magnet
3. Dia magnet
4. Diamagnet
5. Ferromagnet
6. Ferromagnet

Plus Two Physics Magnetism and Matter Four Mark Questions and Answers

Question 1.
Magnetic field lines are the visualization of magnetic field.

1. Write any three properties of magnetic field lines.
2. The arrangement shows two bar magnets placed near each other. Draw the magnetic field lines of the system.

Answer:
1. properties of magnetic field lines:

• The magnetic field lines of a magnet form continuous closed loops.
• The tangent to the field line at a given point represents the direction of magnetic field at that point.
• Flux density of magnetic field represents the strength of magnetic field.
• The magnetic field lines do not intersect

2.

Question 2.
The figure shows the magnetic field of earth.

1. Identify the labels A, B, C. (1)
2. The lines drawn on a map through places that have the same declination are called………(1)
3. The horizontal component of earth’s magnetic field at a place is 0.25 × 10^-4T and the resultant magnetic field is 0.5 × 10^-4 T. Find the dip and the vertical component of the earth’s magnetic field at the place. (2)

Answer:
1. the labels A, B, C:

• A – Magnetic equator
• B – Magnetic axis
• C – Declination

2. Isogonic lines

3. Horizontal component of earth’s magnetic field is
B_H = B cosδ
0.25 × 10^-4 = 0.5 × 10^-4 δ
δ = 60°
Vertical component of earth’s magnetic field is
Bv = B sin δ = 0.5 × 10^-4 sin 60 = 0.43 × 10^-4T.

Plus Two Physics Magnetism and Matter Five Mark Questions and Answers

Question 1.
When a magnetic needle is placed in a non-uniform magnetic field it experiences
1.

• a force but no torque
• a torque but no force
• force and torque
• neither a force nor a torque (1)

2. A bar magnet held perpendicular to a uniform magnetic field as in the figure. If the torque acting on it is to be reduced to 1/4^th by rotating the magnet towards the direction of the field, find the angle through which the magnet is to be rotated. (2)

3. State whether the potential energy of the magnet increases or decreases after rotation. Justify your answer. (2)
Answer:
1. force and torque

2. When the bar magnet is perpendicular to the field Torque is maximum
τ = MBsinθ = MBsin(90) = MB
When rotated through an angle θ, torque is

Angle through which the magnet is to be rotated is 90 – θ = 75.53°

3. Potential energy decreases. Potential energy is minimum when the magnet is parallel to the field. U = MBcosθ. When rotated to 0° (to make magnet parallel to the field) Potential energy decreases.

Students can Download Chapter 4 Planning Questions and Answers, Plus Two Business Studies Chapter Wise Questions and Answers helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus Two Business Studies Chapter Wise Questions and Answers Chapter 4 Planning

Plus Two Business Studies Planning One Mark Questions and Answers

Question 1.
Planning function is required to be performed by all managers at all levels. This feature of planning is
Answer:
Planning is pervasive.

Question 2.
When planning is reduced to black and white, it is known as
Answer:
Formal planning.

Question 3.
Operational plan is undertaken at
Answer:
Lower level management.

Question 4.
Plans are intended to be used repeatedly
Answer:
Standing Plans.

Question 5.
Is a plan which states the expected results of a given future period in numerical terms.
Answer:
Budget.

Question 6.
Which function of management is considered as the base of all other functions?
Answer:
Planning.

Question 7.
Identify the management function which insists on ‘thinking before doing’.
Answer:
Planning.

Question 8.
“These are assumptions on the basis of which plans are formed”. Find the appropriate term used to denote this.
Answer:
Planning premises.

Question 9.
I am a general statement and i provide guidelines in decision making to members of an organization. Who am i?
(a) Procedure
(b) Rule
(c) Policies
(d) Project
Answer:
(c) Policies

Question 10.
‘Mobile phones are restricted in schools’. What type of plan is this? (Method, Programme, Rule, Policy)
Answer:
Rule.

Question 11.
Find out the correct pair.
(a) Objective – Promotion is based on merit only
(b) Policy – Time rate system of wage payment
(c) Rule – No smoking
(d) Method – Make a profit of 40% on capital invested
Answer:
(c) Rule – No smoking

Question 12.
The management of Arun Industries decided to implement the following with effect from the year2007 – “Every employees should mark their attendance before 8 am”. Which aspect of planning is referred here?
Answer:
Rule.

Question 13.
State the type of plan involved in the following two sentences.

1. Promotion is based on merit only
2. Smoking is prohibited in the factory premises.

Answer:

1. Policy
2. Rule

Question 14.
“We sell goods only on cash basis.” Which type of plan is mentioned here?
Answer:
Policy.

Question 15.
Select an example each of objecvitves, goals and policies from the following plans.

1. Increase sales by 10%
2. Every employee should mark attendance before 10 a.m.
3. Maximise the profit.

Answer:

1. Objective
2. Rule
3. Objective

Question 16.
‘Offering 30% of jobs to women.’ What type of plan is it?
Answer:
Policy.

Question 17.
Name the type of plan which provides a basis for interpreting the strategy.
Answer:
Policies.

Question 18.
Name the type of plan in which the minutest details are worked out, that is procedures, rule and budget within the broad framework of policy.
Answer:
Programme.

Question 19.
Name the type of plan which is also a control device from which deviation can be taken care of
Answer:
Budget.

Question 20.
Sony electronics decides to sell television sets through exchange of old television sets. What type of plan is it?
Answer:
Strategy.

Question 21.
Which plan suggests acts and non-action of employees?
Answer:
Rules.

Question 22.
Detect the differences in the following statements contained in a firm’s plan.

1. We sell goods only on Cash basis
2. Smoking is prohibited in the factory Premises.

Answer:

1. Policy
2. Rule

Question 23.
Which among the following is not a limitation of planning?
(a) It reduces flexibility
(b) It is futuristic
(c) Does not guarantee success
(d) Planning is pervasive
i) a&b ii) b&d iii) a, b&d iv)c
Answer:
(ii) b&d

Question 24.
Match the following.

Answer:
a – ii
b – v
c – i
d – iii

Question 25.
Classify the following as single use plan and standing plan.
Budget, Method, Rule, Programmes, Procedure & Policies
Answer:
1. Single use Plan
Budget, Programme.
2. Standing Plan
Method, Rule, Procedure, Policies.

Plus Two Business Studies Planning Two Mark Questions and Answers

Question 1.
What is planning?
Answer:
Planning – Meaning:
Planning is deciding in advance what to do and how to do. It is one of the basic managerial functions. Planning is closely connected with creativity and innovation. Planning involves setting objectives and developing appropriate courses of action to achieve these objectives.

Question 2.
State any two consequences if there was no planning.
Answer:

1. If there was no planning employees would be working in different directions.
2. The management would not be able to achieve.

Plus Two Business Studies Planning Three Mark Questions and Answers

Question 1.
In a classroom discussion, Kalesh argued that planning is a function to be performed only at the top-level management. But Suresh is of the opinion that planning is required at all levels of management.

1. Do you support the argument of Kalesh or Suresh?
2. Justify your answer

Answer:
1. support the argument of Suresh
2.Planning function is required to be performed by the managers at all levels. Board of Directors plan at top level, Functional managers at departmental level and foreman at lower level. The degree and importance of planning depend on the level at which it is undertaken.

Question 2.
“Planning is needed in every function and at every level”. Explain.
Answer:
Planning function is required to be performed by the managers at all levels. Board of Directors plan at top level, Functional managers at departmental level and foreman at plant level. The degree and importance of planning depend on the level at which it is undertaken.

Question 3.
Planning is not a guarantee of success of a business. Comment.
Answer:
It is right to say that planning is not a guarantee of success of business. Since it based on assumptions regarding future and assumptions cannot be hundred percent accurate.

Question 4.
How does planning help in co-ordination?
Answer:
Planning makes co-ordination of various activities, departments and groups relatively easy. Co-ordination of departmental operations is facilitated by planning through the establishment of common goals.

Plus Two Business Studies Planning Four Mark Questions and Answers

Question 1.
“Planning is a continuous process”.

1. Do you agree?
2. Explain

Answer:
1. Yes.

2. Planning is an ongoing and dynamic process. Business environment undergoes constant changes and accordingly, plans have to be modified. The completion of one plan requires the other plan to be undertaken. Hence planning is a never-ending activity.

Question 2.
Match the following.

Answer:

Question 3.
What do you mean by “Single Use Plan” and “Standing Plan”?
Answer:
Types of Plans
1. Single-use plan:
A single-use plan is developed for a one-time event or project. Such plans are not to be repeated in future. E.g. budgets, programmes, projects, etc.

2. Standing plan:
A standing plan is used for activities that occur regularly over a period of time. E .g. policies, procedures, methods and rules.

Plus Two Business Studies Planning Five Mark Questions and Answers

Question 1.
“Forecasting is the essence of planning.”

1. Do you agree?
2. Explain.

Answer:
1. Yes.

2. Forecasting is the essence of planning. Forecasting involves assessing the future. Forecasting is a process of predicting relevant future situations that are likely to affect the activities of the organisation. Customer’s demand, competition, government policies, etc. can be assessed through forecasting. Forecasting helps an organisation to prepare plan efficiently and effectively.

Question 2.

1. Explain the following diagram and identify the management function.
2. Explain its features.

Answer:
1. management function.

2. Features of planning:

• Planning is goal oriented
• It is the primary function of management
• It is required at all levels of management
• Planning is a continuous process
• Planning is futuristic (forward looking)
• It is a decision making function
• It is a mental process

Question 3.
The Board of Directors of Karunya Ltd. decided to implement the following plans in their personnel department during the year 2006.

1. Filling up the vacancies through promotion
2. Selection of workers through various tests such as aptitude test, trade test, interview, etc.
3. Newly selected workers should be given two weeks apprenticeship training.
4. All employees should mark their attendance before 8 am.
5. Increase production of a product by 10% in the year 2018-19.

You are required to

• Classify the plans adopted by Karunya Ltd.
• Establish the reasons for such classification.

Answer:

1. Policy – Guide in decision making
2. Procedure – Manner in which activities are performed
3. Programmes – All activities necessary for achieving a given objective
4. Rules – Rule is a rigid policy which cannot be altered.
5. Objective – Target to be achieved.

Question 4.
“Planning, the primary function of management, suffers from a number of limitations.” Elucidate.
Answer:
Limitations of Planning

1. Planning makes the activities rigid.
2. Long term plans are insignificant in the rapidly changing business environment.
3. It reduces creativity.
4. It involves cost.
5. It involves a lot of time.
6. Planning does not guarantee success.

Plus Two Business Studies Planning Eight Mark Questions and Answers

Question 1.
“No enterprise can achieve its objectives without systematic planning.”

1. Do you agree with this statement?
2. Give reasons in support of your answer.

Answer:
Importance of Planning
1. Planning provides directions:
By stating in advance how work is to be done planning provides direction for all actions.

2. Planning reduces the risk of uncertainty:
Planning enables an organisation to predict future events and prepare to face unexpected events.

3. Planning reduces wasteful activities:
Planning serves as the basis of co-ordinating the activities and efforts of different departments and individuals. It helps to eliminate useless and redundant activities.

4. Planning promotes innovative ideas:
Since planning is thinking in advance, there is scope for finding better and different methods to achieve the desired objectives.

5. Planning facilitates decision making:
Planning helps in decision making by selecting the best alternative among the various alternatives.

6. Facilitates control:
Planning provides the basis for control. Planning specifies the standard with which the actual performance is compared to find out deviation and taking corrective action.

Question 2.
Briefly explain the steps in planning.
Answer:
Planning Process (Steps in Planning)
1. Setting Objectives:
The first step in planning

2. Developing premises:
Planning is based on certain assumptions about the future. These assumptions are called planning premises. Forecasting is important in developing planning premises.

3. Identifying alternative courses of action:
The next step in planning is to identify the alternative courses of action to achieve the objectives.

4. Evaluating alternative Courses:
The pros and cons of various alternatives must be evaluated in terms of their expected cost and benefits.

5. Selecting an alternative:
After evaluating the alternatives the manager will select that alternative which gives maximum benefit at minimum cost.

6. Implement the plan:
Implementation of a plan means putting plans, into action so as to achieve the objectives of the business.

7. Follow up action:
Plans are to be evaluated regularly to check whether they are being implemented and activities are performed according to schedule.

Students can Download Chapter 6 Staffing Questions and Answers, Plus Two Business Studies Chapter Wise Questions and Answers helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus Two Business Studies Chapter Wise Questions and Answers Chapter 6 Staffing

Plus Two Business Studies Staffing One Mark Questions and Answers

Question 1.
Which functions of management helps in obtaining right people and putting them on the right jobs.
Answer:
Staffing.

Question 2.
Name the process concerned with searching for prospective candidates for vacant job position.
Answer:
Recruitment.

Question 3.
Name the function which is concerned with discovering the sources of manpower required and tapping these sources.
Answer:
Recruitment.

Question 4.
It is the process of searching for prospective employees and stimulating them to apply for jobs in the organisation Identify the concept.
Answer:
Recmitment.

Question 5.
Selection starts where ends.
Answer:
Recruitment.

Question 6.
Which among the following is not a case of external recruitment?
(a) Advertisement
(b) Transfer
(c) Employment
(d) Field trip
Answer:
(b) Transfer.

Question 7.
Since more candidates will be rejected than hired through this process, it is described as a negative process. Identify the process?
Answer:
Selection.

Question 8.
Shifting of an employee from one position to another without changes in status and remuneration is called
Answer:
Transfer.

Question 9.
“It is the breaking up of a job into basic elements or operations and studying in details each of the operations to know the nature and characteristics of the job.” This is called; (job specification, job analysis, job identification, job study)
Answer:
Job analysis.

Question 10.
The management of XY Ltd., asks the labour unions to provide a list of candidates for the vacancy of two persons in the office. Identify the source and explain.
Answer:
External sources of recruitment.

Question 11.
The final year students of National Institute of Management were sent to various industrial concerns for practical training. Identify the type of training and state its relevance.
Answer:
Internship training.

Question 12.
Vestibule training is given
Answer:
Outside the job; inside the factory.

Question 13.
Vijay chemicals selected 15 workers for their chemical plant. They intend to train the workers without effecting normal work. Suggest the best method of training.
Answer:
Vestibule training.

Question 14.
This is a method of training where business units make agreement with professional and vocational institutes to provide practical experience. Identify the method of training mentioned here.
Answer:
Internship training.

Question 15.
Face to face contact between the employer and candidate is called
Answer:
Interview

Question 16.
Which one of the following functions is not related with staffing function?
(a) Recruitment of employees
(b) Selection of employees
(c) Compensation of employees
(d) Motivation of employees
Answer:
(d) Motivation of employees

Question 17.
Mr. Sajan is working as Human Resource Manager of an automobile manufacturing unit. One of the following combinations represents his functions. Identify it.
(a) Recruitment, branding, dividend decision
(b) Selection, training, recruitment
(c) Selection, recruitment, marketing
(d) Training, pricing, promotion
Answer:
(b) Selection, training, recruitment

Question 18.
Mr. Abraham seeks new employees for his business. Name any two external sources of recruitment.
Answer:

1. Advertising
2. Empolyment exchange

Question 19.
Mr. Mohan Kumar, the HR Manager of Global Bank Ltd. wants to appoint 50 computer operators for their different branches in Kerala from internal sources. Name any two internal sources forthe recruitment.
Answer:

1. Transfer
2. Promotion

Question 20.
The cheapest method of recruitment is
Answer:
Internal sources of recruitment.

Question 21.
The training method of shifting employee from one job to another is called
Answer:
Job rotation.

Question 22.
Which one of the following is not an On the Job Training method?
(a) Apprenticeship training
(b) Case studies
(c) Computer modelling
(d) Programme instructions
Answer:
(a) Apprenticeship training

Question 23.
is a measure of individual’s potential for learning new skills.
Answer:
Aptitude test.

Question 24.
Which among the following statements are fake?
(a) Training is job oriented process and development is career oriented process.
(b) Internal sources of recruitment motivates the existing staff.
(c) Recruitment is a positive process.
(d) None of the above.
Answer:
(d) None of the above.

Question 25.
Match the following.

A	B
a) Orientation	a) It is a negative process
b) Casual callers	b) Introducing the selected employees
c) Selection	c) External sources of recruitment

Answer:
a → b
b → c
c → a

Plus Two Business Studies Staffing Two Mark Questions and Answers

Question 1.
What do you mean by staffing?
Answer:
Meaning:
Staffing is concerned with determining the manpower requirement of enterprise and includes functions like recruitment, selection, placement, promotion, training, growth and development and performance appraisal of employees in the organization.

Question 2.
Staffing is an important function of management in all organisations. Explain, in brief, any 4 reasons.
Answer:
Importance of Staffing

1. Helps in discovering and obtaining competent personnel for various jobs.
2. Makes for higher performance, by putting right person on the right job.
3. Ensures continuous survival and growth of the enterprise.
4. Helps to ensure optimum utilization of human resources.
5. Improves job satisfaction and morale of employees.

Question 3.
What is recruitment?
Answer:
It is the process of searching for prospective employees and stimulating them to apply for the job in the organisation.

Question 4.
What is selection?
Answer:
Selection:
Selection is the process of identifying and choosing the best person out of a number of prospective candidates for a job.

Plus Two Business Studies Staffing Three Mark Questions and Answers

Question 1.
Why recruitment is regarded as a Positive Process and selection is a negative process.
Answer:
Recruitment is Positive Process because it is concerned with attracting qualified and competent individuals to apply for a job while selection is choosing the best among them and rejecting the unsuitable candidates. So selection is regarded as a negative process.

Question 2.
What is training?
Answer:
Training:
Training is any process by which the aptitudes, skills and abilities of employees to perform specific jobs are increased.

Question 3.
You know that tests are conducted to know the level of ability, knowledge, interest, aptitude, etc. of a particular candidate. Can you suggest an appropriate test for the following and justify.

1. Data entry operator
2. KSRTC driver
3. Personnel manager

Answer:

1. Trade test
2. Trade test
3. Interest test

Question 4.
What are the functions of Human Resource Management?
Answer:
Functions of Human Resource Management

1. Recruitment, i.e., search for qualified people.
2. Analysing jobs, collecting information about jobs to prepare job descriptions.
3. Developing compensation and incentive plans.
4. Training and development of employees.
5. Maintaining labour relations
6. Handling grievances and complaints.
7. Providing for social security and welfare of employees.
8. Maintaining relation with trade unions.

Plus Two Business Studies Staffing Four Mark Questions and Answers

Question 1.
Matha Ltd. invited applications for 20 sales representatives through an advertisement in a daily newspaper. 106 applications were received out of which nine were rejected due to lack of sufficient experience and qualification. The remaining applicants have undergone a written test and an interview. After this, the most efficient 20 applicants were selected. Identify the two major activities processes mentioned in the above situation and also differentiate between them.
Answer:
The above activities are recruitment and selection. The following are the difference between them.

Recruitment	Selection
1) It is the process of searching for candidates and making them apply for the job	1) It is the process of selection of most suitable candidates
2) It is a positive process	2) It is a negative process
3) It is simple	3) It is complex
4) It is less expensive	4) It is more expensive
5) Recruitment is the first stage	5) Selection follows the recruitment

Question 2.
Excel Sugars is a newly established sugar company where a large number of employees are required for different jobs.

1. As a commerce student can you say which source of recruitment is suitable?
2. Why?

Answer:
Excel Sugars is a newly established business organisation. So Internal sources of recruitment is not possible. The company can select employees from various external sources. External sources of Recruitment
a. External Sources:
Selection of employees from outside the enterprise is known as external recruitment.
The important external sources of recruitment are:

1. Direct Recruitment:
Under the direct ‘ recruitment, a notice is placed on the notice-board of the enterprise specifying the details of the jobs available. Job seekers assemble outside the premises of the organisation on the specrfied date and selection is done on the spot. It is suitable for filling casual vacancies.

2. Casual callers:
Many reputed business organisations keep a database of unsolicited applicants in their office. These list can be used for recruitment.

3. Advertisement:
Advertisement in newspapers or trade and professional journals is generally used when a wider choice is required.

4. Employment Exchange:
Employment exchanges keep records of job seekers and will be supplied to business concern on the basis of their requisition.

5. Placement Agencies and Management Consultants:
These agencies compile bio-data of a large number of candidates and recommend suitable names to their clients.

6. Campus Recruitment:
Business enterprises may conduct campus recruitment in educational institutions for selecting young and talented candidates.

7. Recommendations of Employees:
Applicants introduced by present employees, ortheirfriends and relatives may prove to be a good source of recruitment.

8. Labour Contractors:
Labour contractors maintain close contacts with labourers and they can provide the required number of unskilled workers at short notice.

9. Web Publishing:
There are certain websites specifically designed and dedicated forthe purpose of providing information to the job seekers.

Question 3.
Classify the following as internal and external sources of recruitment

1. Advertisement
2. Transfer
3. Campus recruitment
4. Promotion
5. Employment Exchange
6. Job Contractors

Answer:
Internal sources of recruitmentTransfer, Promotion. External sources of recruitment – Advertisement, Campus recruitment, Employment exchange, Job contractors.

Question 4.
In a classroom debate, Jith argues that recruitment and selection are same. Anoop argues that both are different.

1. Whom do you support? Give justification.
2. If you are supporting Anoop, which one comes first?

Answer:
1. We can support the argument of Anoop Staffing Process.
a. Manpower planning:
It is concerned with forecasting the future manpower needs of the organisation, i.e. finding outnumber and type of employees need by the organisation in future.

b. Recruitment:
Recruitment may be defined as the process of searching for prospective employees and stimulating them to apply for jobs in the organisation.

c. Selection:
Selection is the process of selecting the most suitable candidates from a large number of applicants.

d. Placement and Orientation:
Placement refers to putting the right person on the right job. Orientation is introducing the selected employee to other employees and familiarising him with the rules and policies of the organisation.

e. Training and Development:
The process of training helps to improve the job knowledge and skill of the employees. It motivates the employees and improve their efficiency.

f. Performance Appraisal:
Performance appraisal means evaluating an employee’s current and past performance as against certain predetermined standards.

g. Promotion and Career Planning:
Promotion means movement of an employee from his present job to a higher level job.

h. Compensation:
Compensation refers to all forms of pay or rewards going to employees. It may be in the form of direct financial payments like wages, salaries, commissions and indirect payments like employer paid insurance and vacation.

Selection:
Selection is the process of identifying and choosing the best person out of a number of prospective candidates for a job.

2. Recruitment is the first process.

Question 5.
Explain any four methods of Off the Job Training.
Answer:
Off the Job Method:
It refers to those methods under which an individual is provided training away from the work place. It means learning before doing.
The important Off the Job Methods are:

a. Classroom Lectures/Conferences:
The lecture approach is well adapted to convey specific information such as rules, procedures or methods. The use of audio-visuals can often make a formal classroom.

b. Films:
They can provide information and demonstrate skills.

c. Case Study:
Trainee studies the cases to determine problems, analyses causes, develop alternative solutions and select the best solution to implement.

d. Computer Modelling:
It stimulate the work environment by programming a computer to imitate the realities of the job and allows learning to take place without the risk or high cost.

e. Vestibule Training:
Under this method, separate training centres are set up to give training to the new employees. Actual work environment is created in that centre and employees used the same material, equipment, etc. which they use while doing the actual job.

f. Programmed Instruction:
Here information is broken into meaningful units and these units are arranged in a proper way to form a logical and sequential learning package.

Plus Two Business Studies Staffing Five Mark Questions and Answers

Question 1.
Distinguish between internal sources and external sources of recruitment.
Answer:

Internal Source	External Source
1. It is a quick process	1. It is lengthy process
2. This process is cheaper	2. This process is costly
3. The existing staff is motivated	3. The existing staff is dissatisfied
4. Choice of candidate is limited. Less fresh talent	4. More talented and fresh candidates are available
5. It is less time consuming process	5. It is more time consuming process

Question 2.
Identify the following types of training.

1. Its purpose is to familiarize the existing employees with the latest methods.
2. The employee has to rotate from one job to another.
3. Emphasis is given to learning by doing.
4. A large number of persons are to be trained at the same time for the Same kind of work.
5. It is for introducing a new employee to the organisation.

Answer:

1. Refresher Training
2. Job Rotation
3. Apprenticeship Training
4. Vestibule Training
5. Induction Training

Question 3.
List down the advantages of training to the employees.
Answer:
Benefits to the Employee

1. Training helps in securing promotion and career growth.
2. Increased performance by the individual helps him to earn more.
3. Training helps to reduce the chances of accident and wastages.
4. Training increases the satisfaction of employees

Question 4.
Explain the importance of staffing in management.
Answer:
Importance of Staffing

1. Helps in discovering and obtaining competent personnel for various jobs.
2. Makes for higher performance, by putting right person on the right job.
3. Ensures continuous survival and growth of the enterprise.
4. Helps to ensure optimum utilization of human resources.
5. Improves job satisfaction and morale of employees.

Question 5.
Training helps to increase the efficiency of employees Explain.
Answer:
1. On the Job Method:
Under this method, the employee is given training when he is on the job. It means learning while doing.
The important On the Job Methods are:

a. Apprenticeship Programme:
Under apprenticeship training, a trainee is put under the supervision of a master worker.

b. Coaching:
In this method, the superior guides and instructs the trainee as a coach.

c. Internship Training:
It is a joint programme of training in which vocational and professional institutes enter into an agreement with business enterprises for providing practical knowledge to its students.

d. Job Rotation:
Here the trainee is transferred from one job to another job or from one department to another department so that he can learn the working of various sections.

2. Off the Job Method:
It refers to those methods under which an individual is provided training away from the workplace. It means learning before doing.
The important Off the Job Methods are:

a. Classroom Lectures/Conferences:
The lecture approach is well adapted to convey specific information such as rules, procedures or methods. The use of audio-visuals can often make a formal classroom.

b. Films:
They can provide information and demonstrate skills.

c. Case Study:
Trainee studies the cases to determine problems, analyses causes, develop alternative solutions and select the best solution to implement.

d. Computer Modelling:
It stimulate the work environment by programming a computer to imitate the realities of the job and allows learning to take place without the risk or high cost.

e. Vestibule Training:
Under this method, separate training centres are set up to give training to the new employees. Actual work environment is created in that centre and employees used the same material, equipment, etc. which they use while doing the actual job.

f. Programmed Instruction:
Here information is broken into meaningful units and these units are arranged in a proper way to form a logical and sequential learning package.

Plus Two Business Studies Staffing Eight Mark Questions and Answers

Question 1.
Explain briefly steps involved in staffing.
Answer:
Staffing Process
1. Manpower planning:
It is concerned with forecasting the future manpower needs of the organisation, i.e. finding outnumber and type of employees need by the organisation in future.

2. Recruitment:
Recruitment may be defined as the process of searching for prospective employees and stimulating them to apply for jobs in the organisation.

3. Selection:
Selection is the process of selecting the most suitable candidates from a large number of applicants.

4. Placement and Orientation:
Placement refers to putting the right person on the right job. Orientation is introducing the selected employee to other employees and familiarising him with the rules and policies of the organisation.

5. Training and Development:
The process of training helps to improve the job knowledge and skill of the employees. It motivates the employees and improve their efficiency.

6. Performance Appraisal:
Performance appraisal means evaluating an employee’s current and past performance as against certain predetermined standards.

7. Promotion and Career Planning:
Promotion means movement of an employee from his present job to a higher level job.

8. Compensation:
Compensation refers to all forms of pay or rewards going to employees. It may be in the form of direct financial payments like wages, salaries, commissions and indirect payments like employer-paid insurance and vacation.

Question 2.
Aparna textiles decided to open a new Branch in Ernakulam. For the new showroom, they estimated 3 cashiers, 30 salesmen, 10 supervisors.

1. As a commerce student can you suggest the important sources for recruiting for the above vacancies?
2. Explain its advantages and disadvantages.

Answer:
a. Internal Sources:
It refers to the recruitment for jobs from within the organisation. It includes:
1. Transfer:
It involves shifting of an employee from one job to another without change in responsibility or compensation.

2. Promotion:
It refers to shifting of a person from lower position to a higher position carrying higher status, responsibility and more salary.

b. External Sources:
Selection of employees from outside the enterprise is known as external recruitment.
The important external sources of recruitment are:

1. Direct Recruitment:
Under direct recruitment, a notice is placed on the notice-board of the enterprise specifying the details of the jobs available. Job seekers assemble outside the premises of the organisation on the specified date and selection is done on the spot. It is suitable for filling casual vacancies.

2. Casual callers:
Many reputed business organisations keep a database of unsolicited applicants in their office. This list can be used for recruitment.

3. Advertisement:
Advertisement in newspapers or trade and professional journals is generally used when a wider choice is required.

4. Employment Exchange:
Employment exchanges keep records of job seekers and will be supplied to business concern on the basis of their requisition.

5. Placement Agencies and Management Consultants:
These agencies compile bio-data of a large number of candidates and recommend suitable names to their clients.

6. Campus Recruitment:
Business enterprises may conduct campus recruitment in educational institutions for selecting young and talented candidates.

7. Recommendations of Employees:
Applicants introduced by present employees, or their friends and relatives may prove to be a good source of recruitment.

8. Labour Contractors:
Labour contractors maintain close contacts with labourers and they can provide the required number of unskilled workers at short notice.

9. Web Publishing:
There are certain websites specifically designed and dedicated for the purpose of providing information to the job seekers.

Question 3.
Mr. Tom the newly appointed personnel manager of Hindustan Ltd. was given full responsibility for hiring people for the company to fill various positions in the production department.

1. He is confused as to which recruitment sources he would use?
2. Can you help him in this regard?

Answer:
a. Internal Sources:
It refers to the recruitment for jobs from within the organisation It includes:
1. Transfer:
It involves shifting of an employee from one job to another without change in responsibility or compensation.

2. Promotion:
It refers to shifting of a person from lower position to a higher position carrying higher status, responsibility and more salary.

b. External Sources:
Selection of employees from outside the enterprise is known as external recruitment.
The important external sources of recruitment are:

1. Direct Recruitment:
Under the direct ‘ recruitment, a notice is placed on the notice-board of the enterprise specifying the details of the jobs available. Job seekers assemble outside the premises of the organisation on the specified date and selection is done on the spot. It is suitable for filling casual vacancies.

2. Casual callers:
Many reputed business organisations keep a database of unsolicited applicants in their office. This list can be used for recruitment.

3. Advertisement:
Advertisement in newspapers or trade and professional journals is generally used when a wider choice is required.

4. Employment Exchange:
Employment exchanges keep records of job seekers and will be supplied to business concern on the basis of their requisition.

5. Placement Agencies and Management Consultants:
These agencies compile bio-data of a large number of candidates and recommend suitable names to their clients.

6. Campus Recruitment:
Business enterprises may conduct campus recruitment in educational institutions for selecting young and talented candidates.

7. Recommendations of Employees:
Applicants introduced by present employees, or their friends and relatives may prove to be a good source of recruitment.

8. Labour Contractors:
Labour contractors maintain close contacts with labourers and they can provide the required number of unskilled workers at short notice.

9. Web Publishing:
There are certain websites specifically designed and dedicated for the purpose of providing information to the job seekers.

Question 4.
The banking recruitment board gave an advertisement for selection of candidates to various posts in the bank. A large number of applications has been received. Can you suggest the various steps that have to be followed by the board to choose the right candidates?
Answer:
Process of Selection
1. Preliminary Screening:
Preliminary screening helps the manager to eliminate unqualified job seekers.

2. Selection Tests:
Various tests are conducted to know the level of ability, knowledge, interest, aptitude, etc. of a particular candidate. The various types of tests are:

1. Intelligence Tests: This is one of the important psychological tests used to measure the level of intelligence quotient (IQ) of an individual.
2. Aptitude Test: It is a measure of an individual’s potential for learning new skills.
3. Personality Tests: Personality tests provide clues to a person’s emotions, reactions, maturity and value system, etc.
4. Trade Test: These tests measure the existing skills of the individual.
5. Interest Tests: Interest tests are used to know the pattern of interests or involvement of a person.

3. Employment Interview:
Interview is a formal, in-depth conversation conducted to evaluate the applicant’s suitability for the job.

4. Reference and Background Checks:
Many employers request names, addresses, and telephone numbers of references for the purpose of verifying information and, gaining additional information on an applicant.

5. Final Selection:
The final decision has to be made from among the candidates who pass the tests, interviews and reference checks.

6. Medical Examination:
After selection, the candidates are required to appear for a medical examination for ensuring that he is physically fit for the job.

7. Job Offer:
After a candidate has cleared all the hurdles in the selection procedure, he is formally appointed through an order. It contains the terms and conditions of the employment, pays scale, joining time, etc.

8. Employment Contract:
Basic information that should be included in a written contract of employment are job title, duties, responsibilities, date of joining, pay and allowances, hours of work, leave rules, disciplinary procedure, work rules, termination of employment, etc.

Students can Download Chapter 4 Moving Charges and Magnetism Questions and Answers, Plus Two Physics Chapter Wise Questions and Answers helps you to revise the complete Kerala State Syllabus and score more marks in your examinations.

Kerala Plus Two Physics Chapter Wise Questions and Answers Chapter 4 Moving Charges and Magnetism

Plus Two Physics Moving Charges and Magnetism NCERT Text Book Questions and Answers

Question 1.
A Circular coil of wire consisting of 100 turns, each of radius 8.0cm carries a current of 0.40A. What is the magnitude of the magnetic field B at the centre of the coil?
Answer:
Given n = 100, r = 8.0cm = 8 × 10^-2
I = 0.4A, B = ?
At the centre of circular coil

= π × 10⁴T = 3.1 × 10^-4T.

Question 2.
A uniform field equal to 1.5T exists in a cylindrical region of radius 10.0cm, its direction parallel to the axis along east to west. A wire carrying current of 7.0A in the north to south direction passes through this region. What is the magnitude and direction of the force on the wire if

1. The wire intersects the axis?
2. The wire is turned from N-S to north-east-north-west direction.
3. The wire in the N-S direction is lowered from the axis by a distance of 4.0cm?

Answer:
1. F = \(\mathrm{Bl} \ell\) = 1.5 × 7 × \(\frac{20}{100}\) or F = 2.1 N acting vertically downwards.

2. Force will again be 2.1N.

3. F = \(\frac{1.5 \times 7 \times 16}{100}\) = 1.68N.

Question 3.
Two long and parallel straight wires A and B carrying currents of 8.0A and 5.0A in the same direction are separated by a distance of 4.0cm. Estimate the force on a 10cm section of wire A.
Answer:
Given I₁ = 8.0A, l₂ = 5.0A, r = 4.0cm = 0.04m
l = 10cm = 0.10m
Since

(direction is given by Fleming left-hand rule).

Plus Two Physics Moving Charges and Magnetism One Mark Questions and Answers

Question 1.
A straight wire of length 0.5 metre and carrying a current of 1.2 ampere is placed in uniform magnetic field of induction 2 tesla. The magnetic field is perpendicular to the length of the wire. Find the force on the wire is
Answer:
F = i/B = 1.2 × 0.5 × 2 = 1.2 N

Question 2.
To convert a galvanometer into a ammeter, one needs to connect a.
(a) low resistance in parallel
(b) high resistance in parallel
(c) low resistance in series
(d) high resistance in series
Answer:
(a) low resistance in parallel

Question 3.
A coil carrying electric current is placed in uniform magnetic field.
(a) torque is formed
(b) e.m.f is induced
(c) both a and b are correct
(d) none of these
Answer:
(a) torque is formed

Question 4.
Direction of motion of unit the positive test charge gives direction electric field. Direction of motion of…….gives direction of magnetic field.
Answer:
Unit north pole.

Question 5.
A magnetic system with zero dipole moment
(a) Solenoid
(b) current carrying coil
(c) current loop
(d) toroid
Answer:
(d) Toroid.

Question 6.
Find odd one regarding polarity solenoid, torroid, current carrying loop, bar magnet.
Answer:
Torroid (In this case North and South pole are absent).

Question 7.
The nature of path when a charged particle is projected 30° to the direction of magnetic field. (Helix, cycloid, straight line, parabola).
Answer:
Helix

Question 8.
What is solenoid?
Answer:
An insulated copper wire wound in the form of cylinder is called solenoid.

Question 9.
Write mathematical expression for ampere’s theorem.
Answer:
∫B.dl = µ₀I

Plus Two Physics Moving Charges and Magnetism Two Mark Questions and Answers

Question 1.
The figure shows a long straight conductor carrying a current I. A magnetic field is produced around the conductor.

What is the magnitude of the magnetic induction at a point ‘P’ which is at a distant ‘x’ from the conductor?
What is the shape of the magnetic line of force?

Answer:
1. B = \(\frac{\mu_{0} I}{2 \pi x}\). Magnetic field is directed in to the plane of paper.

2. Circular.

Question 2.
A particle of mass 6.65 × 10^-27 kg having positive charge equal to two times of electron, moves with a speed of 6 × 10⁵ m/s in a direction perpendicular to that of a given magnetic field of flux density 0.4 weber/m². Find the acceleration of the particle.
Answer:

q = 2e, v = 6 × 10⁵ m/s
B = 0.4, m = 6.65 × 10^-27 kg
∴ acceleration,

a = 1.15 × 10¹³ m/s².

Question 3.
Classify in to true or false.

1. The magnetic field in the middle of current carrying solenoid depends up on cross sectional area.
2. The magnetic field depends up on current.
3. The magnetic field depends up on the material of the core.
4. The magnetic field depends up on total numbers of turns per unit length.

Answer:

1. False
2. True
3. True
4. True

Question 4.
A short straight conductor carries current I

1. Write the expression for magnetic field due to this conductor.
2. Represent graphically the variation of magnetic field with distance from the wire.

Answer:
1. dB = \(\frac{\mu_{0}}{4 \pi} \frac{|d| \sin \theta}{r^{2}}\)

2.

Plus Two Physics Moving Charges and Magnetism Three Mark Questions and Answers

Question 1.
The magnetic field along the axis of a circular coil is found to be B = \(\frac{\mu_{\mathrm{o}} \mathrm{Ia}^{2}}{2\left(\mathrm{r}^{2}+\mathrm{a}^{2}\right)^{3 / 2}}\)
1. What is the magnetic field along the axis if r>>a
2.

• Compare the above magnetic field with the electric field along the axis of an electric dipole
• What is the equation of magnetic dipole moment?

Answer:
1. B = \(\frac{\mu_{0} / a^{2}}{2 r^{3}}\)

2.

• Electric field due to electric dipole, E = \(\frac{1}{4 \pi \varepsilon_{0}} \frac{P}{r^{3}}\) magnetic field due to magnetic dipole B = \(\frac{\mu_{0}}{4 \pi} \frac{m}{x^{3}}\).
• Magnetic moment m = IA

Question 2.
The circuit diagram for verifying Ohm’s Law is given below, A student unknowingly connects a galvanometer in the place of the ammeter.

1. What will happen to the galvanometer?
2. What modification has to be made in the galvanometer if he still wants to use the galvanometer in place of the ammeter?
3. Assuming voltmeter to be an ideal one, what will happen if the student interchanges the position of the voltmeter and ammeter?

Answer:

1. Galvanometer will be damaged.
2. use a shunt resistance.
3. No current flows, because an ideal voltmeter has infinite resistance.

Question 3.
Consider a galvanometer with a full scale deflection of 1 m A and resistance 100Ω.

1. How is the device connected in the circuit?
2. How can it be converted to an ammeter with full scale deflection 1 ampere?

Answer:
1. Connected in series.

2.

by connecting a shunt resistance. 0.1Ω in parallel with galvanometer, we can convert galvanometer in to ammeter.

Question 4.
Two infinitely long straight parallel wires carry currents I each as shown in fig.

1. Which law helps to find direction of magnetic field around a current carrying conductor?
2. What is the magnitude, direction of the magnetic fields at A, and C?

Answer:
1. Right hand grip rule.

2. The magnitude, direction of the magnetic fields at A, and C:

• A – outward to the plane of paper
• C-Inward to the plane of paper.

Question 5.
Analyze the figure and answer the following questions.

1. What is the nature of force between these conductors is……….
2. What is the field due to I₁ at second conductor?
3. What is the force experienced per unit length of II^nd conductor?

Answer:

1. Attractive
2. B= \(\frac{\mu_{0} d_{1}}{2 \pi r}\)
3. f = \(\frac{\mu_{0} l_{1} l_{2}}{2 \pi r}\)

Question 6.
“I am very light and present in every matter. When I move along the equator from east to west, I am pushed up. When I am stationary, no force”.

1. Name the force and write its expression.
2. Who am I?
3. What would happen if moved at the poles?

Answer:

1. Lorentz force in earth’s magnetic field F =qvB
2. Electron
3. The earth’s magnetic field at poles is perpendicular to the earth surface. When an electron move, it is pushed to one side, parallel to earth’s surface.

Plus Two Physics Moving Charges and Magnetism Four Mark Questions and Answers

Question 1.
The internal connections of a moving coil galvanometer is given in the fig (i) and fig (ii)

1. What is the use of moving coil galvanometer?
2. Which figure(i) or figure(ii) is used to measure Voltage?
3. Write an expression for resistance required to convert the moving coil galvanometer in to voltmeter.
4. If a very small resistance (eg, copper wire) is used to convert moving coil galvanometer in to voltmeter, will it work properly?

Answer:

1. Moving coil galvanometer is used to detect the presence of current
2. The instrument shown in figure (2) is used to measure voltage.
3. Resistance is connected in series with galvanometer. R = \(\frac{\mathrm{V}}{\mathrm{I}_{\mathrm{g}}}\) – G
4. No, A high resistance is required to convert galvanometer in to voltmeter.

Question 2.
When a charged particle enter normal to a uniform magnetic field, it take a circular path.

1. Name the particle accelerator using this principle.
2. Explain the working of that particle accelerator with relevant theory.
3. The neutrons can’t be accelerated using this partide accelerator. Why?

Answer:
1. Cyclotron.

2. Cyclotron:
a. Uses:
It is a device used to accelerate particles to high energy.

b. Principles:
Cyclotron is based on two facts

• An electric field can accelerate a charged particle.
• A perpendicular magnetic field gives the ion a circular path.

c. Working:

At certain instant, let D₁ be positive and D₂ be negative. Ion (+ve) will be accelerated towards D₂ and describes a semicircular path (inside it). When the particle reaches the gap, D₁ becomes negative and D₂ becomes positive.

So ion is accelerated towards D₁ and undergoes a circular motion with larger radius. This process repeats again and again. Thus ion comes near the edge of the dee with high K.E. This ion can be directed towards the target by a deflecting plate.

3. Charge of neutron is zero. Only charged particle can be accelerated using particle accelerated.

Question 3.
A current flows through a circular loop of radius r is shown in the figure.

1. What is the direction of magnetic field at ‘o’? (1)

2. Derive an equation for magnetic field at ‘o’ due to the circular loop carrying current i? (2)

3. If the loop splits into two equal halves as shown in figure. (1)

What will be the magnetic field at the center ‘o’?
Answer:
1. B = \(\frac{\mu_{0} I}{2 r}\) in t0 the plane of paper

2. Magnetic field on the axis of a circular current loop:
Consider a circular loop of radius ‘a’ and carrying current T. Let P be a point on the axis of the coil, at distance x from A and r from ‘O’. Consider a small length dl at A.
The magnetic field at ‘p’ due to this small element dl,
dB =\(\frac{\mu_{0} \mathrm{Idl} \sin 90}{4 \pi \mathrm{x}^{2}}\)

[since sin 90° -1]
The dB can be resolved into dB cosΦ (along Py) and dB sinΦ (along Px). Similarly consider a small element at B, which produces a magnetic field ‘dB’ at P. If we resolve this magnetic field we get.
dB sinΦ (along px) and dB cosΦ (along py¹)
dB cosΦ components cancel each other, because they are in opposite direction. So only dB sinΦ components are found at P, so total filed at P is

from ∆AOP we get x = (r² + a² )^1/2

Let there be N turns in the loop then,

Point at the centre of the loop:
When the point is at the centre of the loop, (r = 0) Then,

3. Zero

Question 4.
A boy connects a galvanometer directly to a cell of emf 1.5v to measure a current through a load 1Ω.

1. Which instrument can be used to measure the current in such a circuit?
2. What changes should be made in the galvanometer to measure such a high current? Explain using a circuit diagram.
3. The boy connected the galvanometer into a high current measuring device and he connected the device parallel to the load. What will be the observation. Justify.

Answer:
1. Ammeter

2.

A galvanometer can be converted into an ammeter by a low resistance (shunt) connected parallel to it.
Theory:
Let G be the resistance of the galvanometer, giving full deflection fora current I_g. To convert it into an ammeter, a suitable shunt resistance ‘S’ is connected in parallel. In this arrangement, Ig current flows through Galvanometer and remaining (I-I_g) current flows through shunt resistance.
Since G and S are parallel
P.d Across G = p.d across S
I_g × G =(I-I_g)S
S = \(\frac{\lg \mathrm{G}}{\left(1-\mathrm{l}_{\mathrm{g}}\right)}\)
Connecting this shunt resistance across galvanometer we can convert a galvanometer into ammeter.

3. Ammeter is a low resistance device. Hence it draws high current. This high current will damage it.

Question 5.
An electric charge will experience a force in uniform electric field. Similarly a moving charge experience a magnetic force (Lorentz) in magnetic field. The SI unit of magnetic field intensity is defined in terms of Lorentz Force.

1. Write the expression for magnetic Lorentz force.
2. Mention any two difference between electric field arid magnetic field.
3. Give an account of work done by Magnetic Lorentz force on moving charge and corresponding change in K.E.

Answer:
1.

2. Electric field is due to a charge, either in motion or at rest. Magnetic field is due to the motion of charge. Direction of electric force is colinear to electric field. Direction of magnetic force is perpendicularto magnetic field.

3. If velocity (displacement) is perpendicular to Lorentz force the work done will be zero and hence there will no change in K.E.

Question 6.
“Moving coil Galvanorrieter is a device used for detecting very feeble current”.

1. What is the working principle of a moving coil galvanometer?
2. Describe the construction and working of a moving coil galvanometer.
3. When a high current is passed through a moving coil galvanometer, it will get destroyed. How?

Answer:
1. Principle:
A conductor carrying current when placed in a magnetic field experiences a force, (given by Fleming’s left hand rule), τ = NIAB.

2.

A moving coil galvanometer consists of rectangular coil of wire having area ‘A’ and number of turns ‘n’ which is wound on metallic frame and is placed between two magnets. The magnets are concave in shape, which produces radial field.
Working :
Let T be the current flowing the coil, Then the torque acting on the coil. τ = NIAB, Where A is the area of coil and B is the magnetic field.

This torque produces a rotation on coil, thus fiber is twisted and angle (Φ). Due to this twisting a restoring torque (τ = KΦ) is produced in spring. Under equilibrium, we can write
Torque on the coil = restoring torque on the spring
NIAB = KΦ
Φ \(=\left(\frac{\mathrm{BAN}}{\mathrm{K}}\right)\) I
The quantity inside the bracket is constant for a galvanometer.
Φ ∝ I
The above equation shows that the deflection depends on current passing through galvanometer.

3. High current will produce large amount of heat. This heat will destroy coils in the galvanometer.

Question 7.
When a current carrying conductor is placed in a magnetic field it experiences a force.
1. Arrive at the expression forthe force experienced by the conductor. (2)
2. A conductor carrying current I direct out of the plane of the paper is lying in the magnetic field as in Fig. Draw the direction of force experienced by the conductor. (1)

3. If the conductor is lying parallel to the field what will be the force? (2)
Answer:
1. Consider a rod of uniform cross section ‘A’ and length ‘l’ Let ‘n’ be the number of electrons per unit volume (number density). ‘v_d’ be the drift velocityof electrons for steady current ‘I’.
Total number of electrons in the entire volume of rod =nAl
Charge of total electrons = nA l .e
‘e’ is the charge of a single electron.
The Lorentz force on electrons,

2.

3. Zero

Question 8.
A long straight conductor carrying current is placed near a current carrying circular loop as in the figure.

1. If B₁ is the field of the ring and B₂ the field due to straight conductor what will be the direction of B₁ and B₂ at O. (1)

2. The current through the loop and the conductor are 2A and the conductor is at as distance 20cm from the centre of loop. What should be the diameter of the loop so that the net field at O is zero. (3)
Answer:
1. B₁ into the plane and B₂ out of the plane.

2. B₁ is the field of the ring and B₂ the field of due to straight conductor.
B = B₁ – B₂ = 0
B₁ = B₂

2a = 40π × 10^-2m = 1,256m
Diameter d = 1.256 m.

Question 9.
A charged particle is travelling in the figure.

1. Name the force experienced by the charge in the region II. (1)
2. Give the expression for the net force experienced by the charge in the region II. (1)
3. If the charge reaches the region III without any change in its initial direction of motion find the velocity of the charged particle in terms of E and B. (2)

Answer:
1. Lorentz Force

2. F = q (E + v × B)

3. Electric and magnetic fields are perpendicular to each other and also perpendicular to the velocity of the particle. If the total force on the charge is zero and the charge will move in the fields undeflected. This happens when
qE = qvB or v = \(\frac{E}{B}\).

Question 10.
The medical diagnostic technique called magnetic resonance imaging (MRI) requires that patient lie in a strong magnetic field. It consists of two large solenoids, placed above and below.

1. What is solenoid?
2. Which law help you to find magnetic field due to solenoid? State the law.
3. Obtain an expression for magnetic field due to solenoid using the above law.
4. If the diameter of one of the MRI coil is increased without changing the current, does the magnetic field that it produce at its centre increases, decreases or stay the same? Justify.

Answer:
1. An insulated conducting wire wound in the form of cylinder is called solenoid.

2. Ampere’s circuital law:
Ampere’s circuital theorem states that the line integral of the magnetic field around any closed path in free space is equal to µ₀ times the net current passing through the surface.

3.

Consider a solenoid having radius Y. Let ‘n’ be the number of turns per unit length and I be the current flowing through it.

In order to find the magnetic field (inside the solenoid ) consider an Amperian loop PQRS. Let ‘l‘ be the length and ‘b’ the breadth

Applying Amperes law, we can write

Substituting the above values in eq (1), we get
Bl = µ₀ l_enc (2)
But l_enc = n l I
where ’nl ’ is the total number of turns that carries current I (inside the loop PQRS)
∴ eq (2) can be written as
Bl = µ₀nIl
B = µ₀ nI
If core of solenoid is filled with a medium of relative permittivity µ_r, then
B = µ₀µ_rnl

4. No change. Magnetic field is independent of radius.

Plus Two Physics Moving Charges and Magnetism Five Mark Questions and Answers

Question 1.
You are supplied with a galvanometer, resistor, and some connecting wires.

1. Using a circuit diagram, show how will you convert the given galvanometer into an ammeter.
2. Find the expression for the shunt resistance in the circuit.
3. A galvanometer is to be converted into an ammeter of range 0 – 1 A. Galvanometer has resistance 100Ω and the current for full scale deflection is 10mA. Find the length of the nichrome wire to be used as shunt.

Given, Resistivity ρ= 1.1 x 10^-6Ωm
Diameter of the wire = 1mm
Answer:
1.

2. Let I_g be the current through the galvanometer of resistance R_G and the shunt resistance be r_s.
Let I be the current to be measured by the converted ammeter.
We can write,
I_gR_G = (I – I_g)r_s
∴ r_s = \(\frac{I_{g} R_{G}}{\left(1-I_{g}\right)}\)

3. Given I = 1A
I_g = 10mA
R_G = 100Ω
Diameter = 1mm

Question 2.
Consider a conductor carrying current ‘I’, P is a point at a distance away from the conductor.

1. What is the direction of magnetic field at P? (1)
2. What are the factors affecting magnetic field at P due the element dl carrying current i? (1)
3. Derive an expression for magnetic field at P, if the current carrying conductor has infinite length? (2)
4. Draw a graph connecting Intensity of magnetic
   field and distance. (1)

Answer:
1. In to the plane of paper

2. dB = \(\frac{\mu_{0}}{4 \pi} \frac{|d| \sin \theta}{r^{2}}\)

• Current I
• Length of element dl
• sin of angle between element and line joining mid point of element and point.
• Inversely proportional to square of the distance between element and point.

3. Long straight conductor:
Consider a long straight conductor carrying ‘I’ ampere current. To find magnetic field at ‘P’, we construct a circle of radius r (passing through P).

According to Ampere’s circuital law we can write

4.

Question 3.
A student placed a rectangular loop carrying current in between the pole pieces of two magnetics and found that the loop is rotating.

1. What is the net force on the loop?
2. Write the expression for the torque experienced by the loop in vector form.
3. At what position will the coil be in stable equilibrium?
4. A wire of length 4m is bent in the form of a circular coil of single turn. A current 1A is flowing through the wire. If the coil is placed in a magnetic field of 0.4T find the maximum torque experienced by the coil.

Answer:
1. Zero

2.

3. θ = 0, τ = 0, Potential energy is minimum (Area vector of the coil is parallel to the direction of magnetic field.)

4. I = 4m
2πr = 4
r = \(\frac{4}{2 \pi}\)
Area = A = πr²
Maximum torque = NIAB = 1 × 1 × π × \(\left(\frac{4}{2 \pi}\right)^{2}\) × 0.4
= 0.509 Nm

Question 4.
Ampere’s theorem helps to find the magnetic field in a region around a current carrying conductor.

1. Draw the variation of intensity of magnetic field with the distance from the axis of a current carrying conductor.
2. A conductor carrying a current I is bent as shown in the figure. Apply Ampere’s theorem at the regions 1 and 2 shown in the figure.

Answer:
1.

2.

Question 5.
The force acting on a moving charge in a magnetic field is called magnetic Lorents force.

1. Write the equation of force experienced by a charged particle moving in a magnetic field.
2. Using the equation derive an expression for the force acting on a current carrying conductor of length T in a magnetic field B.
3. “A charge can move in a helical path in a magnetic field”. Do you agree with it? Explain.

Answer:
1.

2. Consider a rod of uniform cross section ‘A’ and length ‘ l ’. Let ’n’ be the number of electrons per unit volume (number density). ‘v_d’ be the drift velocity of electrons for steady current ‘I’.
Total number of electrons in the entire volume of rod = nA l
Charge of total electrons = nA l .e
‘e’ is the charge of a single electron.
The Lorentz force on electrons,

3. Yes, When an electron moves in a magnetic field with an angle θ, the electron undergoes for helical motion. The velocity of electron has two components, usinθ and ucosθ.

The component usinθ produces circular motion and ‘ucosθ’ produces translational motion. The combined effect of circular motion and translation motion will be helical motion.

Question 6.
A long wire is bent into a circular coil of one turn having radius ‘R’ and a current T is passed through it

1. Name the law to find the direction of magnetic field due to this current loop
2. Find an expression for magnetic field produced by this current loop at its centre
3. If the same wire is bent to a smaller radius Y having ‘n’ turns and send same current through it. Find the ratio of magnetic field at the centre in two cases.

Answer:
1. Right hand screw rule.

2. The magnetic field at a distance × from centre of loop is given by

3.

If wire is bend into smaller radius of n turns.

B₂ = n² B₁

Question 7.

A gas chamber is filled with hydrogen and a magnetic field is applied to it, then exposed to γ-ray. The γ-ray hits the hydrogen atom and produces high energy electron, low energy electron and positron (electron having + ve charge). The above photograph represents the trajectory of the particles. [Here magnetic field is applied Out of the plane of photo graph]

1. Which force drives the particle in a circular path and write the mathematical from.
2. Obtain a general expression for radius of the circular path.
3. Analyse the figure and match the columns given below.

Answer:
1. Magnetic Lorentz force

2. The centripetal force required for rotation is given magnetic Lorentz force Hence we can write

3. Analyse the figure and match the columns given below:

• Low energy electrons – B
• High energy electron – C
• Positron – A

Question 8.
A proton, an electron, a neutron, and an alpha particle are entering a region of uniform magnetic field with same velocities. The tracks of these particles are labelled.

1. Identify the tracks of each particle. (1)
2. Write the expression for the force experienced by a charged particle in the magnetic field in vector form. (1)
3. If the proton is moving at 90° to the uniform magnetic field what will be the change in kinetic energy of the proton? Give reason. (1)
4. An electron with energy 1 keV is entering a uniform magnetic field of 0.04T at an angle 60° with the field. Predict the path of the electron and find the characteristics of the path. (2)

Answer:
1. Identify the tracks of each particle:

• Path 1 – proton
• Path 2 – alpha particle
• Path 3 – neutron
• Path 4 – electron

2.

3. Zero. Since the force is perpendicular to the direction of velocity work done is zero.

4. KE = 1 keV = 1 × 10³ × 1.6 × 10^-19 = 1.6 × 10^-16


= 8.39 × 10^-3.

Question 9.
A current carrying conductor is bent in the form of a circular ring and is placed in the plane of the paper.

1. What is the direction of the magnetic field at the centre of the ring? (1)
2. Arrive at the expression for the magnetic field at a point on the axis of the ring. (3)
3. Another identical ring carrying the same current is brought with its axis perpendicular to the axis of the first as in figure. Find the magneticfield at the common centre. Calculate the angle between the net magnetic field and the axis of any one of the coils. (1)

Answer:
1. Out of the plane of the ring.

2.

Consider a circular loop of radius ‘a’ and carrying current ‘I’. Let P be a point on the axis of the coil, at distance x from A and r from ‘O’. Consider a small length dl at A. The magnetic field at ‘p’ due to this small element dl,

[since sin 90° -1]
The dB can be resolved into dB cosΦ (along Py) and dB sinΦ (along Px). Similarly consider a small element at B, which produces a magnetic field ‘dB’ at P.

If we resolve this magnetic field we get. dB sinΦ (along px) and dB cosΦ (along py¹) dB cosΦ components cancel each other, because they are in opposite direction. So only dB sinΦ components are found at P, so total filed at P is
B = ∫dBsinΦ

but from ∆AOP we get, sinΦ = a/x
∴ We get,

Let there be N turns in the loop then,

At the center of the loop,
r= 0

3. Magnetic fields are as shown in the fig.

The diagonal gives the resultant field.

Question 10.
An electron revolving round the nucleus acts as a magnetic dipole.

1. Which force provides the centripetal force for electron? (1)
2. Write the expression for the magnetic dipole moment of electron in vector form. What is the angle between direction of the magnetic moment and direction of angular momentum? (2)
3. A charge 2mC is moving through a circular path of radius 0.15m with frequency 1000Hz. Find the magnetic moment associated with the charge path. (2)

Answer:
1. Electrostatic force between electron and the nucleus.

2. Vectorially

The magnetic moment of the electron is opposite in direction to the angular momentum.
∴ Angle = 180°.

3. Revolving charge behaves as a current loop. Hence Magnetic field is given as

I = \(\frac{q}{T}\) = qv = 2 × 10^-3 × 100 = 0.2A
Magnetic moment = IA = 0.2 × π × 0.15²
= 0.0141 Am.

Question 11.
You are supplied with a galvanometer, resistor, and some connecting wires.

1. Using a circuit diagram, show how will you convert the given galvanometer into an ammeter. (1)
2. Find the expression for the shunt resistance in the circuit. (2)
3. A galvanometer is to be converted into an ammeter of range 0 -1 A. Galvanometer has resistance 100Ω and the current for full-scale deflection is 10mA. Find the length of the nichrome wire to be used as shunt. (3)

Given, Resistivity ρ = 1.1 × 10^-6Ωm
Diameter of the wire = 1 mm
Answer:
1.

2. Let I_g be the current through the galvanometer of resistance R_G and the shunt resistance be r_s. Let I be the current to be measured by the converted ammeter.
We can write,

3. Given I = IA
I_g = 10mA
R_G = 100Ω
Diameter = 1mm