Kerala Syllabus Class 10 Physics Model Question Paper Set 1

Practicing Physics Question Paper Class 10 Kerala Syllabus Set 1 English Medium helps identify strengths and weaknesses in a subject.

Physics Class 10 Kerala Syllabus Model Question Paper Set 1

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 7, 10, 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

I. 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.
When the current was doubled, the heat produced in the conductor became 4 times. If so, what happens to the heat produced if the current is halved? (halved/ quartered)
Answer:
quartered

Question 2.
Statement : Danger signals are made of red colour
Reason : Red is having shorter wavelength ,so it deviates the least.
(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) Statement is correct, reason is incorrect
(d) Statement is incorrect; reason is correct.
Answer:
(c) Statement is correct, reason is incorrect

Question 3.
Some statements are given.
i) Mechanical advantage of first order lever is equal to one or greater than one or lesser than one.
ii) Mechanical advantage of second order lever is always less than one.
iii) Mechanical advantage of third order lever is always less than one.
iv) Mechanical advantage of third order lever is always greater than one.

Choose the correct option.
a) i & ii
b) i & iv
c) i & iii
d) none of these
Answer:
c) i & iii

Question 4.
Find the relation in the first pair and complete the second.
Focal length : metre
Power of lens : ________
Answer:
dioptre

Section – B

II. Write down the answers to the questions 5 to 11. Questions 7 and 10 have choices. Each question carries 2 score. (7 × 2 = 14)

Question 5.
Why do second-order levers always have a mechanical advantage greater than 1?
Answer:
Because the effort arm (distance from fulcrum to effort) is always longer than the load arm (distance from fulcrum to load), less effort is needed to lift the load, resulting in a mechanical advantage greater than 1.

Question 6.
(a) What do you mean by one kilowatt hour?
(b) How much is 1 unit of electric energy in joules?
Answer:
(a) One kilowatt hour or one unit of electric energy is the energy consumed by an appliance with 1000 W (1kW) power in one hour.
(b) 1 unit of electrical energy = lkWh
= 3.6 × 106 J

Question 7.
A) In the split ring commutator of a DC motor, semicircular rings are used. What is the need for this?
OR
Answer:
A) In a motor, the split ring commutator rotates along with the armature. The position of the half rings in the split ring commutator changes continuously. So, the direction of current through the coil changes after every half rotation. Thus, continuous rotation is possible in a motor.

B) Current flowing through a solenoid is represented below.

a) What is the polarity at A?
b) What is the polarity at B?
Answer:
B) a) North pole
b) South pole

Question 8.
Differentiate between primary colours of light and secondary colours of light?
Answer:
With red, green and blue lights, we can create not only white light, but also all other colours of light. So, these colours are called primary colours. The coloured light formed by combining any two primary colours is a secondary colour of light.
Eg: Yellow, magenta, cyan.

Question 9.
Define the following terms of a lens.
a) Optic centre
b) Centre of curvature
Answer:
a) The midpoint of a lens
b) The centre of the imaginary spheres of which the sides of the lens are parts.

Question 10.
A) Statements related to a stepdown and stepup transformers is given below.Choose the correct statement
related to each and tabulate them.
• Thick wires are used in the primary
• Thin wires are used in the primary
• The primary has lesser number of turns than the secondary
• The secondary has less number of turns than the primary
Answer:

Stepup transformer	Stepdown transformer
• Thick wires are used in the primary	• Thin wires are used in the primary
• The primary has lesser number of turns than the secondary	• The secondary has less number of turns than the primary

Or
Question 10.
B) What do you mean by transmission loss? Write down any two methods to minimise energy loss while transmitting electricity over long distances through conducting wires.
Answer:
When electrical energy is transmitted to distant places through conducting wires, energy is wasted in the form of heat.This is transmission loss.

Methods to minimise energy loss

1. Use suitable metal wires with low resistivity.
2. Increase voltage and decrease current without changing power.
3. Use thicker wires

Question 11.
Why are long inclined roads built in hairpin roads on ghats and other such places?
Answer:
The concept of mechanical advantage of inclined plane is utilised here. As we increase the length of an inclined plane the mechanical advantage increases. So the inclined roads are built with maximum length.

Section – C

III. Write down the answers to questions 12 to 17. Questions 12 and 17 have choices. Each question carries 3 score. (5 × 3 = 18)

Question 12.
A) (a) Mark load, fulcrum and effort in the figure given below.

(b) Name the device. Which order of lever is shown above?
(c) Which arm is longer in such lever ?What will be the mechanical advantage?
Answer:
(a)

(b) Tongs. Third order lever
(c) Load arm is longer Mechanical advantage is less than one

OR
B) A movable pulley is used to lift 600 N load. When the rope is pulled 8 m by applying a force of 300 N then the
load raises by 4 m. Prove that there is no gain in the work even though there is a gain in the effort applied.
Answer:
The displacement of the object, s = 4 m
Weight of the object, F = 600N
Work done on the object = F × s = 600 × 4 = 2400 J
The displacement of the rope on applying 300 N force,
s₁ = 8 m
F₁ = 300 N
The work done by the force we applied
= F₁ s₁
300 × 8 = 2400 J
The work done on the object and the work done by the effort are equal.

Question 13.
Three students are doing the same experiment by using the following sets of solenoids and magnets, (magnets are identical, and the solenoids are wound in clockwise direction with the same type of wire.)

a) Why does the galvanometer needle deflect while the magnet moves toward the solenoid?
b) Among the experiments 1, 2, and 3 identify the solenoids which produce the same direction of deflection when the magnet is moved towards the coil. Why?
c) What happens to deflection of galvanometer needle when the number of turns of coil is increased in this experiment?
Answer:
a) The galvanometer deflects due to the flow of electric current,

b) Experiment! and 2
In both experiments 1 and 2, the direction of deflection of the needle is the same because the polarity of the bar magnet that is moving into the coil is the same(the south pole of the magnet is moving into the coil).

c) Deflection of galvanometer needle increases

Question 14.
a) Write two applications of reflection of sound?
b) What is meant by multiple reflection of sound?
c) Write two methods by which you can reduce the harmful effects of reflection of sound in big halls.
Answer:
a) Reflection of sound is utilized in
• Soundboards
• Curved ceilings in halls

b) Reflected sound waves get reflected again. It is called multiple reflection of sound.

c) Make the walls rough, provide a large number of ventilators.

Question 15.
Observe figure (a) (b) and (c). Write down in table by observing the change in the path of light rays passing through the convex lens through different paths from point A.

(c)

(a) A ray of light from a point which is parallel to the optic axis incident on a convex lens	___ (i) ___
(b) A ray of light passing through the optic centre	___ (i) ___
(c) A ray of light passing through the principal focus on same side of the object incident on a convex lens	___ (iii) ____

Answer:
a) Passes through the principal focus on the other side after refraction.
ii) Passes undeviated along the straight line without undergoing refraction.
ii) Passes parallel to the optic axis after refraction.

Question 16.
Answers to questions based on the figure given below.

a) How many times does a ray of light undergo refraction when it passes through a water droplet?
b) What about the internal reflection?
c) W hat are the colours seen at the outer edge and at the inner edge of the rainbow?
Answer:
a) Light ray undergoes refraction two times.
b) It undergoes internal reflection one time.
c) Colour at the outer edge-red Colour at the inner edge -Violet

Question 17.
A) On a heating appliance it is marked 529 W, 230 V.
a) What do each of these mean?
b) What would be the power of this appliance if 100 V is supplied?
Answer:
a) 529 W, 230 V indicates that the appliance operating at voltage of 230 V consumes 529 W power.
b)

OR
B) A Circuit is made as shown below using nichrome wire and aluminium wire of equal length (4 cm) and equal area of cross section, ammeter, rheostat and 9 V, 50 W eliminator.

Pass current through the circuit for about 2 minutes.
(a) Which conductor becomes hotter.Why?
(b) What is the magnitude of current in the nichrome wire and aluminium wire?
(c) Write down any two factors that influence the quantity of heat produced in a current carrying conductor.
Answer:
a) The nichrome wire
It is because its resistance is greater than that of the aluminium wire.
b) Magnitude of current in the nichrome wire and aluminium wire is the same.
c)
• Current (I)
• Resistance of the conductor(R)
• Time for which current flows(t) (any two)

Section – D

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

Question 18.
A) A conducting wire AB is bent into a loop as shown in the figure.

A battery is connected to the ends of the conductor.
a) When the switch is turned on, find the direction of the magnetic field around the conductor at points A and B .
b) State the law used for this.
c) Explain how to find the direction of the magnetic field in a conducting loop.
Answer:
At A-anticlockwise, At B -clockwise
Right hand thumb rule
The direction of the current is from positive to negative. At the side which coil faces us, the current flows in the clockwise direction. As the current flow in the clockwise direction, the direction of the magnetic field will be into the coil.

OR
Question 18.
B) Observe the picture and answer the questions.

a) Identify the device shown in the schematic diagram.
b) Name the labelled parts.
c) What is its working principle?
d) What is the energy conversion taking place in this device?
Answer:
a) Moving coil loudspeaker
A-Voice coil
B-Paper diaphragm
C-Field magnet
D-Connecting wires E-Soft iron shielding

b) Motor principle

c) Energy conversion: Electrical energy to sound energy