Kerala Syllabus Class 10 Physics Model Question Paper Set 5

Practicing Physics Question Paper Class 10 Kerala Syllabus Set 5 English Medium helps identify strengths and weaknesses in a subject.

Physics Class 10 Kerala Syllabus Model Question Paper Set 5

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 6, 9, 12, 17 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.

Identify the devices from the options given below.
a) (i) -second order lever, (ii)-Fixed pulley
b) (i) – third order lever, (ii) – Movable pulley
c) (i) – Second order lever, (ii)-Movable pulley
d) (i)- Third order lever, (ii)-Fixed pulley
Answer:
c) (i) – Second order lever, (ii)-Movable pulley

Question 2.
Find the most appropriate statement related to a telescope.
a) The objective lens has a shorter focal length and the eyepiece lens has a longer focal length.
b) The objective lens has a longer focal length and the eyepiece has a shorter focal length.
c) Objective lens and eyepiece lens are concave lenses.
d) Objective lens will be concave lens and eyepiece lens will be convex lens.
Answer:
b) The objective lens has a longer focal length and the eyepiece has a shorter focal length.

Question 3.
Statement: A current is induced in a coil when a magnet is moved towards or away from it. Reason: The relative motion between the coil and the magnet changes the magnetic flux through the coil.
a) Both statement and reason are true; the reason explains the statement.
b) Both statement and reason are true; but the reason does not explain the statement.
c) Both the statement and the reason are incorrect.
d) Statement is incorrect; reason is correct.
Answer:
a) Both statement and reason are true; the reason explains the statement.

Question 4.
Some statements related to electrical power is given.
i. Electric power is measured in joules.
ii. 1 kilowatt-hour is equal to 1000 joules.
iii. Power is the quantity of work done by an electrical appliance per unit time.
iv. Power, P = y

Which are the correct statements related to it.
a) i and ii only
b) iii and iv only
c) ivonly
d) iii only
Answer:
d) iii only

Section – B

Write down the answers to the questions 5 to 11. Questions 6 and 9 have choices. Each question carries 2 score. (7 × 2 = 14)

Question 5.
The primary and secondary currents of a transformer are 2 A and 4 A respectively. The output voltage of this transformer is 100 V.
a) Identify the transformer.
b) Calculate the primary voltage of the transformer.
Answer:
a) Stepdown Transformer
b) V_p × I_p = V_s × I_s
∴ V_p = (V_s × I_s)/I_p
= (100 × 4)/2
= 200 V

Question 6.
(a) A conductor is held above and parallel to a magntic needle.

a) What causes the magnetic needle to deflect when the switch is turned on?
b) Suggest two ways to reverse the direction of this deflection.
Answer:
a) A magnetic field is formed around a current carrying conductor. This magnetic field can exert a force on a magnetic needle. The magnetic needle was deflected due to the interaction between this magnetic field and the magnetic field around the magnetic needle.

b) • Change the direction of current
• Arrange the conductor below the compass needle

OR
Question 6.

The magnetic field of which magnets are depicted? Explain.
Answer:
a) Bar magnet
b) Electromagnet (solenoid)
The magnetic field lines of the bar magnet and that of the electromagnet are similar. The magnetic strength / magnetism of an electromagnet is temporary and that of a bar magnet is permanent.

Question 7.
Match correctly

Sound Board	Resonance
Resonance Column	Period
Characteristic of wave	Richter scale
Intensity of earthquake	Reflection of sound

Answer:

Sound Board	Reflection of sound
Resonance Column	Resonance
Characteristic of wave	Period
Intensity of earthquake	Richter scale

Question 8.
Complete the following sentences
a) The lens that forms only virtual images is …… (convex lens, concave lens)
b) In a telescope, the objective forms a ……. image of a distant object (small, real and inverted ; magnified, real and inverted)
Answer:
a) concave lens
b) small, real and inverted

Question 9.
(A).a)Name the part of a heating equipment in which the electric energy is converted into heat energy,
b) Name the substance used to make this part.
Answer:
a) Heating coil
b) Nichrome

OR
(B) In a house, 5 CF lamps each of 20 W work for 4 hours, and 4 fans each of 60 W work for 5 hours in a day. What will be the daily consumption of energy shown by the watt-hour meter?
Answer:
Electric energy (in kilowatt hour)
= \(\frac{\text { Power in watt × time in hour }}{1000}\)
Energy consumed by 5 CF lamps
= \(\frac{5 \times 20 \times 4}{1000}\) = 0.4k Wh
Energy consumed by 4 fans
\(\frac{4 \times 60 \times 5}{1000}\) = 1.2 kWh
Daily consumption of energy
= 0.4 + 1.2 = 1.6 kWh = 1.6 kWh

Question 10.
Explain the necessity of gears in vehicles.
Answer:
While going uphill, large wheel is connected to the toothed wheel attached to the engine. When connected to a large toothed wheel, the speed of the vehicle decreases, but its efficiency to rotate increases. To increase the speed of the vehicle, the toothed wheel attached to the engine must be connected to the small toothed wheel that helps to turn the tyre of the vehicle.

Question 11.
Safety must be ensured while working with electric circuits. There are many situations which may lead to an electric shock.
a) What do you mean by electric shock?
b) Write any two first aid measures that should be given to a person who has suffered an electric shock.
Answer:
a) Electric shock is the impact caused by the flow of current through the body,

b) • Rub the body to increase blood circulation and raise body temperature.
• Administer artificial respiration.
• Rub the muscles to restore them to their normal state.
• Start first aid to restart the heart-perform chest compressions rhythmically and forcefully (Cardio Pulmonary Resuscitation).
(any two)

Section – C

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

Question 12.
(A). Inclined planes are often used in situations where objects are to be lifted.
a) What is the work done to lift a 600 N load by 3m?
b) The force applied was 200 N along an inclined plane to lift this load. Displacement of the load was 9 m. What is the work done?
c) Is there a gain in the work done?
Answer:
a) Force, F = 600 N
Displacement, s = 3 m
4rork done, W = Fs
= 600 × 3 = 1800 Nm = 1800J

b) Force, F = 200N
Displacement. s = 9m
Work done, W = 200 × 9 = 1800 Nm = 1800 J

c) There is no gain in work done.

OR
(B). a) A load of 1600 kgwt is suspended from an axle with a diameter of 6 cm. What should be the force applied in newton, to turn a 3 m long lever on one side of the axle, to lift this load? (Consider g = 10 m/s²)
b) In a wheel and axle system ,what happens to the mechanical advantage when radius of wheel increases.
Answer:
a)Mechanical advantage of axle and wheel
= (R/r) = (L/E)
Diameter of the axle = 6 cm
Radius of the axle, r = 3 cm
Load = L = 1600 kgwt
= 1600 × 10 N = 16000 N
Radius of the wheel, R = 300 cm
(L/E) = (R/r)
(16000/E) = (300/3)
Effort, E = 160N

b) As the radius of the wheel increases, the mechanical advantage also increases.

Question 13.
a) If an ultrasonic wave emitted by a transmitter, installed on a ship on the surface of the water, strikes a rock at the bottom of the sea and returns after 0.2 s, what is the distance from the ship to the rock? Consider the speed of ultrasonic waves in seawater as 1522 m/s.
b) Bats make use of ______ sounds for catching prey
Answer:
(a) v = 1522 m/s
t = 0.2s
v = 2d/t
2d = v × t
d = (v × t)/2 = (1522 × 0.2)/2 = 152.2m

(b) UItrasonic

Question 14.
The focal length of a convex lens is 20 cm. An object of height 2 cm is placed on its optic axis is located 40 cm away from the lens. Calculate the distance from the lens to the image. What will be the magnification in this case? What are the characteristics of the image formed?
Answer:
f = 20 cm
h₀ = 2 cm
The object is located at 2f (at 40 cm) of the convex lens. Here, the distance from the lens to the image v = 40 cm.
Magnification = -1
Characteristics of the image: same size, inverted, real

Question 15.
Observe the figure

When the current is from A to B, in which direction does the north pole of each magnetic needle deflect? (Clockwise direction/anticlock wise direction)
Answer:
a) Anticlockwise direction
b) Right hand thumb rule
c) Imagine holding a conductor with your right hand in such a way that the thumb points in the direction of the electric current, the fingers curled around the conductor will indicate the direction of the magnetic field.

Question 16.
Observe the figure.

a) If the magnet is rapidly moved into the coil, what will you observe in the galvanometer?
b) What will be the nature of the current obtained if the magnet is rapidly moved up and down inside the coil?
c) What are the ways to increase the current induced in the coil?
Answer:
a) The galvanometer needle will deflect.

b) The current will be alternating (changes direction).

c) • Moving the magnet faster
• Using a stronger magnet
• Using more turns of wire in the coil

Question 17.
(A) Observe the figure given below and answer the following

a) Which are the occasions when sunlight has to travel greater distance through the atmosphere before reaching the eyes of an observer on the earth?
b) When light reaches the observer after travelling long distances through the atmosphere, which colour reaches the eye? What is the reason?
c) Even after sunset, the western horizon continues to have red colour for some more time. Why?
Answer:
a) In the morning and in the evening sunlight has to travel greater distance.

b) Red. Due to its greater wavelength.

c) During long distant travelling of sunlight, light travels through more of the Earth’s atmosphere. As it does, the shorter blue wavelengths scatter more, leaving the longer wavelength (red)for us to see.That is colours of shorter wavelength would be almost fully lost due to scattering and only red will predominate.

OR
(B) Observe the images related to image formation in the eyes.

a) Which is the image showing an eye with nears ightedness?
b) What are the reasons behind near-sightedness?
c) What is the remedy for this defect?
Answer:
a) B
b) • The size of the eye ball is larger.
• The focal length of the eye lens is low (power high)
c) This can be overcome by using concave lens of suitable power.

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). An electric heater of 1000 £1 works on a 230 V supply
a) Write down the energy change taking place in the electric heater.
b) State the law to find the quantity of heat generated in an electric heater?
c) Calculate the electrical energy consumed when the heater works for three hours.
Answer:
A.a) Electrical energy is converted to heat energy
b) The quantity of heat produced in a current carrying conductor is directly proportional to the square of the current (P), the resistance of the conductor (R) and the time (t) for which the current flows. This is Joule’s law.
c) V = 230 V,
R = 1000Q,
t = 3 hour = 3 x 60 × 60 = 10800 s
H = \(\frac{v^2 t}{R}=\frac{230^2 \times 10800}{1000}\) = 571320 J

OR
(B), Observe the figure.

a) Write down the name of the device.
b) What is it used for?
c) In a house 5 LED lamps each of 20 W works for 5 hours and one laptop of 50 W works for 2 hours daily. Calculate electrical energy consumption in one month in commercial units.
Answer:
a) Watt-hour meter
b) The quantity of electric energy consumed in houses can be measured directly by a watt hour meter.
c) Electric energy (in kilowatt hour)
= [/latex]\frac{\text { Power in watt × time in hour }}{1000}[/latex]
Electric energy consumed by lamps
= \(\frac{5 \times 20 \times 4}{1000}\) = 0.5 units
Electric energy consumed by laptop
\( \frac{4 \times 60 \times 5}{1000} \) = 0.1 units
Total energy consumption in a day
= 0.5 + 0.1 = 0.6 units
Total energy consumption in a month
= 0.6 × 30 = 18 units