Kerala Syllabus Class 10 Physics Model Question Paper Set 4

Practicing Physics Question Paper Class 10 Kerala Syllabus Set 4 English Medium helps identify strengths and weaknesses in a subject.

Physics Class 10 Kerala Syllabus Model Question Paper Set 4

Time: 1 1/2 Hours
Total Score: 40

Instructions:

1. The first 15 minutes is cool-off time. This time is meant for reading the questions and planning your answers.
2. This question paper includes 18 questions in sections A, B, C, D.
3. Questions 5, 11, 13, 15 and 18 contain choices.
4. You need to answer only one of the options provided for each of these choice-based questions.

Section – A

Write down the correct answer by choosing from the given options for questions 1 to 4. Each question carries 1 score. (4 × 1 = 4)

Question 1.
Some characteristics of transformers are given below. Select the correct statements suitable for stepup transformers.
(a) Secondary voltage is greater than primary voltage.
(b) Thick wires are used in the secondary.
(c) Primary voltage is greater than secondary voltage.
(d) The current in the primary coil is greater than that in the secondary coil.
(i) (a), (b) and (d)only
(ii) (a) and (d) only
(iii) (a) only
(iv) (b) only
Answer:
(ii) (a) and (d) only

Question 2.
Select the odd one.
(Scissors, Nut cracker, Common balance, seesaw)
Answer:
Nut cracker

Question 3.
Statement :Humans cannot hear the sound of galton whistle
Reason :The audible range of humans is 20 Hz-20 khz
a) Both the statement and the reason are correct, reason justifies the statement
b) Both the statement and the reason are correct, but the reason does not justify the statement.
c) Both the statement and the reason are incorrect.
d) The statement is incorrect, but the reason is correct.
Answer:
a) Both the statement and the reason are correct, reason justifies the statement

Question 4.
Choose the correctly drawn ray diagram, showing a virtual and magnified image formation.

Answer:

Question 5.
(A)
a) What is the relation between the deviation of component colours of white light through a prism and their wavelength?
b) Classify the colours green, red, indigo and yellow in the descending order of their wavelengths.
Answer:
a) When wavelength increases deviation decreases. When wavelength decreases deviation increases.

b) Red, yellow, green, Indigo.

OR
(B) To get clear vision, the images of near object and distant object should fall on the retina of the eye
a) Name the ability of eyes to get an image on the retina.
b) How does eyes adjust itself to get the image of distant object on the retina?
Answer:
a) Power of accommodation.
b) When we view distant object the ciliary muscles are relaxed and the curvature of the lens decreases. Then focal length of eye lens increases.

Question 6.
Observe the figure

a) If current flows from A to B, find the direction of deflection of conductor AB. (inward, outward)
b) Which is the law that helps you to find the direction of deflection of the conductor.
Answer:
a) Inwards

b) Fleming’s left hand rule

Question 7.
The heat generated in a current carrying conductor can be explained by a famous law.
a) Write the name of this law.
b) Write the mathematical equation for this law, explain each letters used in the equation.
Answer:
a) Joule’s law

b) H = I2Rt or HxI2Rt
H – Heat generated in a conductor
I – Intensity of electric current
R – Resistance of the conductor
t – time for which current flows

Question 8.
Write the factors that influence the natural frequency of an object?
Answer:

1. Length of the object
2. Size of the object
3. Elasticity
4. Nature of the material

Question 9.
The government is promoting the installation of solar panels by giving incentives to boost electricity generation. Explain its significance in the context of the energy crisis.
Answer:
The over use of non-renewable fossil fuels like coal, oil, and natural gas which contribute to pollution and global warming has resulted in an energy crisis for the entire world. Because it is abundant, renewable, environmentally friendly, and accessible even in remote locations, solar energy is an excellent substitute. Solar thermal power plants use the sun’s heat to produce electricity, whereas solar cells directly turn sunlight into electrical power.

In everyday life, gadgets like solar water heaters and stoves can help cut down on the amount of power and fossil fuels used. We can lessen the effects of the energy crisis, conserve resources, and safeguard the environment by utilising more solar energy.

Question 10.
Say whether the following statements are true or false. Correct them if wrong.
a) If the effort comes in between the load and the fulcrum, it is a second order lever.
Answer:
a) False
If the effort comes in between the load and the fulcrum, it is a third order lever,
b) True

Question 11.
A) A transformer has 600 turns in its primary and 1800 turns in its secondary. 450 V is obtained across itssecondary. Then,
a) Which type of transformer is this?
b) What will be the voltage supplied across the primary?
Answer:
a) Stepup transformer

b) \(\frac{\mathrm{V}_{\mathrm{S}}}{\mathrm{~V}_{\mathrm{P}}}=\frac{\mathrm{N}_{\mathrm{S}}}{\mathrm{~N}_{\mathrm{P}}},\)
\(V_P=\frac{V_S \times N_P}{N_S}=\frac{450 \times 600}{1800}\)
Voltage across primary = 150 V

OR
B. Write any two precautions to be taken to avoid electric shock.
Answer:

1. Never handle electric equipment or operate switches when the hands are wet.
2. Do not fly kites near electric lines.
3. Do not handle electrical appliances or operate switches with wet hands.
4. Plug into or unplug from a socket only after turning off the switch.
5. Do not operate high power appliances in a normal socket.
6. Do not touch the inside of a cable TV adapter.

Ensure that the adapter has an insulator cover. (Any two)

Section – C

Write down the answers to questions 12 to 17. Questions 13 and 15 have choices. Each question carries 3 score. (6 × 3 = 18)

Question 12.
100 W bulb works on 230 V supply.
a) If voltage is halved, how much will be the power?
b) If voltage decreases to 1/4 times, how much will be the power?
c) If the voltage is doubled what happen to the bulb?
Answer:
a) \( R=\frac{V^2}{P}=\frac{230^2}{100}\) = 529Ω
When voltage is halved V = 115 V
R = 529Ω
P = \(\frac{V^2}{R}=\frac{115^2}{529}\) = 25W
When voltage is halved,power becomes 1/4 times the original power)
p = 25W

b) Voltage decreases to 1/4 times,V = 57.5 V
R = 529 Q
P = \(\frac{57.5^2}{529}\) = 6.25W
P = 6.25 W

c) Device will be damaged due to high voltage

Question 13.
(A). Below are some of the characteristics associated with the bar magnet and a current carrying solenoid. Classify them and complete the table.
• Magnetism is temporary.
• Magnetism is permanent
• The magnetic poles cannot be interchanged
• The magnetic strength cannot be varied.
• The magnetic strength can be varied.
• The magnetic poles can be interchanged
Answer:

Bar magnet	Current carrying solenoid
Magnetism is permanent	Magnetism is temporary
The magnetic poles cannot be interchanged	The magnetic poles can be interchanged
The magnetic strength cannot be varied.	The magnetic strength can be varied.

OR
(B). Observe the diagram

a) Write the name of this device.
b) Write the energy conversion in this device
c) What is the name of the part ABCD in this device?
Answer:
a) Electric motor
b) Electrical energy is converted into mechanical energy
c) Armature

Question 14.
What are the differences between first, second, and third order levers?
Answer:
First order lever:
In a first order lever, fulcrum comes in between effort and load. The load can be equal to, lesser or greater than the effort. The mechanical advantage of a first order lever is equal to one or greater than one or Lesser than one.

Second order lever:
In a second order lever, the load is always more than the effort. The load comes in between effort and fulcrum. Mechanical advantage of a second order lever is always more than one.

Third order lever:
In a third order lever, the load is always less than the effort. The effort comes in between fulcrum and load. Its mechanical advantage is always less than one.

Question 15.
(A) Draw the ray diagram showing the image formation in a convex lens when the object is placed beyond 2F. Write down the position and characteristics of image.
Answer:

Position of image :Between 2F and F on other side of the lens
Characteristics of image: Inverted, diminished and real.

OR
(B) Match the items in the columns A, B and C appropriately.
Answer:

A	N	C
Magnification	Hi/ho	v/u
Power of lens	1/f	hi negative
Real image	Inverted image	hi, positive

Question 16.
a) What do you mean by carbon footprint?
b) Write any two steps to reduce it?
Answer:
(a) Greenhouse gases are directly and indirectly emitted by individuals, families, organizations, events, services, products, etc. The quantity of such emitted greenhouse gases, converted and expressed as equivalent to the measure of carbon dioxide, is carbon footprint.

(b) Reduce domestic energy consumption
• Avoid wasting food.
• Use public transport.
• Reduce waste by utilising reusable products.

Question 17.
The current in the secondary coil of a transformer with no power loss is 5 A and that in the primary is 0.5 A.
a) What type of transformer is this?
b) If the input voltage of this transformer is 240V, calculate the output voltage.
Answer:
(a) Step down transformer (Secondary current is more than the primary current)

(b) I_s = 5A
I_p = 0.5 A
V_p = 240V
V_s = ?
I_s × V_s = I_p ×  V_p
V_s = \(\frac{V_P \times I_P}{I_S}=\frac{0.5 \times 240}{5}\)= 24V

Section – D

18th question has a choice. Answer any one of the two questions. Each question carries 4 score. (4 × 1 = 4)

Question 18.
(A). Classify the following levers into first, second, and third order lever. Nut cracker, Fishing pole, Scissors, Wheel barrow, Lemon Squeezer, Seesaw, Forceps, Common balance, Fixed pulley, Elbow, Ice tongs
Answer:
First order lever

1. Scissors
2. Seesaw
3. Common balance
4. Fixed pulley

Second order lever

1. Nut cracker
2. Wheel barrow
3. Lemon Squeezer

Third order lever

1. Fishing pole
2. Forceps
3. Elbow
4. Ice tongs

OR
(B). Simple machines are basic mechanical devices that mechanical devices that make work easier.
a) What do you mean by simple machines?
b) There are mainly six types of simple machines. Which are they?
c) What is mechanical advantage(MA)?
d) Mechanical advantage of a wheel and axle is…………..
Answer:
a) Simple machines are devices that change the magnitude of the effect of force or the direction of the force or both. They are devices that make exertion easier.

b) Lever, Pulley, Wheel and axle, Inclined plane, Screw, Wedge

c) Mechanical advantage (MA) is the ratio of the load to the effort. It is a number indicating how many times of the load is the effort. Mechanical advantage is only a ratio. It has no unit.
Mechanical advantage, MA = Load/Effort

d)\(\frac{R(\text { radius’ of wheel })}{r(\text { radius of axle })}\)