Kerala Syllabus Class 10 Physics Model Question Paper Set 3

Practicing Physics Question Paper Class 10 Kerala Syllabus Set 3 English Medium helps identify strengths and weaknesses in a subject.

Physics Class 10 Kerala Syllabus Model Question Paper Set 3

General Instructions:

1. The first 15 minutes is the cool off time. You may – use the time to read and plan your answers.
2. Answer the questions only after reading the instructions and questions thoroughly.
3. Questions with marks series 1, 2, 3 and 4 are categorized as sections A, B, C and D respectively.
4. Five questions are given in each section. Answer any four from each section.
5. Answer each question by keeping the time.

Time: 1½ Hours
Total Score: 40 Marks

Section – A

I. Answer any FOUR questions from 1 to 5. Each question carries 1 score. [4 x 1 = 4]

Question 1.
Choose the odd one and write the reason for that
(Vlt, l²Rt, VQ, VRt)
Answer:
VRt. All others represent the quantity of heat produced due to the flow of current.

Question 2.
What is the voltage of electricity produced in the power stations of our country?
(50Hz, 11V, 11kV, 110kV)
Answer:
11kV

Question 3.
Which of the following has greater refractive index?
(Glass, Water, Diamond, Air)
Answer:
Diamond

Question 4.
On a lens, its power is marked as -1.5 D. Which type of lens is this?
Answer:
Concave lens

Question 5.
Using the relation in the first pair, complete the second pair.
Colour of setting sun: scattering
Rainbow:……
Answer:
Dispersion

II. Answer any FOUR questions from 6 to 10. Each question carries 2 score. (4 × 2 = 8)

Question 6.
Hydrogen is a fuel that can be consider as a fuel of tuture.
a. Write two properties that hydrogen can be consider as a good fuel.
b. Write a situation in which hydrogen is used as a fuel.
Answer:
(a) (i) High calorific value
(ii) Low environment pollution
(b) Used as a fuel in rockets

Question 7.
Find which type of mirror is used in the following situations.
a. Used in the sharp curves to see vehicles from opposite direction.
b. Used by ENT specialists.
Answer:
(a) Convex mirror
(b) Concave mirror

Question 8.
Write the uses of the following devices.
(i) Clamp ammeter
(ii) ELCB
Answer:
(i) To measure current in a circuit without connecting wires.
(ii) Helps to break the circuit automatically whenever there is a current leak.

Question 9.
A conductor deflects in the upward direction when placed east-west direction in a magnetic field. The magnetic field is experiencing in the north south direction.
a. Which is the direction of induced emf in the conductor?
b. Which law helped to find the answer?
Answer:
(a) From east to west.
(b) Fleming’s right hand rule.

Question 10.
Correct the following statements if there is any error.
a. The direction of magnetic field produced when current is passed through a conductor depends on the intensity of electric current.
b. The strength of magnetic field decreases when increasing the distance from a current carrying conductor
c. The direction of magnetic field due to electric current cannot be changed.
Answer:
(a) The direction of magnetic field produced when current is passed through a conductor depends on the direction of electric current.
(c) The direction of magnetic field due to electric current can be changed.

III. Answer any FOUR question from 11 to 15. Each question carries 3 score. (4 × 3 = 12)

Question 11.
Tungsten is used to make filament in incandescent lamps.
a. What are the features of tungsten used here?
b. What is the demerit of this lamp comparing with other lamps?
c. Why nitrogen gas is filled in this lamps?
Answer:
(a) High resistivity, high ductility, high melting point and ability to emit white light when heated.
(b) Loss of energy in the form of heat.
(c) To prevent evaporation of filament.

Question 12.

a. Which defect of eye is shown in the figure?
b. Which are the situations that a person may suffer this defect of vision?
c. How can be correct this defect?
Answer:
(a) Near – sightedness
(b) Size of the eye ball is normal but power of lens is high or power of lens is normal but size of eye ball is larger.
(c) Use concave lens of suitable power.

Question 13.
Write the reason for the following?
a. When spherical raindrops fall fast, it appear as glass rods.
b. Sky and deep reservoirs of water seen in blue colour.
c. In misty mornings, we can see the path of light coming through the trees.
Answer:
(a) Persistence of vision
(b) Scattering
(c) Tyndal effect

Question 14.
a. What are the items used in the experiment done in the classroom related with the scattering of light?
b. After some time the rate of scattering increased in this experiment. Why?
c. How this will affect scattering?
Answer:
(a) A rectangular vessel, water, screen, torch, sodium thio sulphate solution, dilute hydrochloric acid.
(b) Due to the increase in size of sulphur particles in the solution.
(c)(i) As the size of particles increase the rate of scattering also increases.
(ii) If the size of particles is greater than the wavelength of light then scattering is same for all colours.

Question 15.
Solar cell is a system that solve the problems of energy crisis and nature friendly.
a. Which is the principle used for the working of solar cell?
b. Write the energy change take place here.
c. Write two devices that utilizes solar heat directly.
Answer:
(a) Photo voltaic effect
(b) Light energy changes in to electrical energy.
(c) Solar cooker, solar water heater

IV. Answer any FOUR questions from 16 to 20. Each question carries 4 score. (4 × 4 = 16)

Question 16.
Match the following.

Electric bell	Heating effect	Mechanical effect
Fridge	Magnetic effect	Light energy
LED	Mechanical energy	Heat energy
Soldering iron	Light effect	Magnetic energy

Answer:
Electric bell – Magnetic effect – Magnetic energy
Fridge – Mechanical effect – Mechanical energy
LED – Lighting effect- Light energy
Soldering iron – Heating effect – Heat energy

Question 17.
Classify the following statements and give suitable titles.
a. Magnetic strength is permanent.
b. Can vary the amount of magnetic field accordingly.
c. Require electricity for working.
d. Magnetic strength is temporary.
e. Not require electricity for working
f. Magnetic strength not decreasing with time.
g. Cannot vary the the magnetic strength accordingly
h. Magnetic strength decreasing with time.
Answer:
Bar magnet
a
e
g
h
Electro magnet
b
C
d
f

Question 18.

a. Identify the device in the figure.
b. Which type of current is passing through the armature?
c. In which direction does the current flow in the external circuit?
d. What are the uses of R₁ and R₂?
Answer:
(a) DC Generator
(b) AC
(c) From B, to B
(d) (i) Give current induced in the armature to external circuit.
(ii) AC obtained in armature should change to DC in the external circuit.

Question 19.

a. The object of height 2.5 cm illustrated in the figure is replaced with another object of height 1.5 cm, then what will be height of the image?
b. Where will be the position of the object when image is formed 12 cm away?
c. Find the focal length and radius of curvature of the mirror.
Answer:
(a) Magnification,m \(\frac { 1.5 }{ 2.5 }\) = -0.6 When the height of object become1.5.
m = \(\frac { hi }{ ho }\) : hi = m × ho
hi = \(\frac { 1.5 }{ 2.5 }\) × 1.5 = 0.9

(b) v = -12cm;
m = \(\frac { -v }{ u }\); -0.6 = –\(\left(\frac{-12}{u}\right)\); -0.6 = \(\frac { 12 }{ 4 }\)
∴ u = \(\frac { 12 }{ 0.6 }\) = -20 cm

(c) f = \(\frac { uv }{ u+v }\) = \(\frac{(-20) \times(-12)}{(-20)+(-12)}\); \(\frac{20 \times 12}{.32}\) = 7.5 cm; R = 2f = 2 × (-7.5) = -15 cm

Question 20.

Substance	Refractive index
Air	1.0003
Water	1.33
Kerosene	1.44
Turpentine oil	1.47
Crown glass	1.52
Diamond	2.42

a. Which substance in the table has more optical density?
b. If the speed of light through air is 3 x10 m/s, then what will be the speed of light through water?
c. Kerosene and water are taken in a reactangular glass vessel. A laser light is allowed to fall from the bottom of the vessel to the upward slantingly. Whether total internal reflection occurs when the angle of incidence changes? Why?
d. What is the change in the direction of ray of light when it is entering from crown glass to air? (moving towards the normal / moving away from the normal)
Answer:
(a) Diamond

(b) Refrective index of water – 1.33 = \(\frac{3 \times 10^8}{\text { Speed of light through water }}\)
Speed of light through water = \(\frac{3 \times 10^8}{1.33}\) = 2.55 × 10⁸ m/s

(c) No, because here ray of light entering from lower optical density to higher optical density.

(d) Deviate from the normal. Because ray of light is entering from crown glass of more optical density to air of low optical density.