Kerala Syllabus Class 9 Physics Model Question Paper Set 4 English Medium

Teachers recommend solving Kerala Syllabus 9th Standard Physics Question Paper Set 4 to improve time management during exams.

Kerala Syllabus Std 9 Physics Model Question Paper Set 4 English Medium

Time: 1½ Hours
Max Score: 40 Marks

Instructions

• First 15 minutes is given as cool off time. This time is to be spent for reading and understanding the questions.
• Answer the questions according to the directions.
• Score and time to be considered while answering.

I. Answer any three questions from 1 to 4. (1 score each) (3 × 1 = 3)

Question 1.
Impossible position-time graph is

Answer:
B

Question 2.
Which of these figures representing the path of light through a glass slab is correct?

Answer:
B

Question 3.
Give an example of inertia of motion
Answer:

• When a bus stops suddenly, the passengers tend to fall forward.
• A participant in long jump competition, runs some distance and then jumps.
• A ball set rolling on a horizontal floor keeps moving forward.

Question 4.
1 kgwt = ______ N
Answer:
1 kg wt = 9.8 N

II. Answer any Seven questions from 5 to 13. (2 score each) (7 × 2 = 14)

Question 5.
Describe a scenario where displacement is zero, but distance is not.
Answer:
If a person walks 5 m north and then 5 m south through the same path, their displacement is zero because they end up at their starting point. However, the distance travelled is 10 m, as it is the total path length covered. This illustrates how displacement considers direction, while distance does not.

Question 6.
Write any two examples of circular motion.
Answer:

• Motion of Artificial satellites
• Whirling a stone tied to a string
• Rotation of fan blades

Question 7.
Describe the benefits of using small prisms in reflectors of motorcycles.
Answer:
Many small prisms are used in reflectors used in motor cycles. Light falling on the prisms undergoes total internal reflection and reflects back without loosing the intensity of light. The image can be seen with greater visual clarity.

Question 8.
Observe the figure

When the cad Is suddenly struck. what happens to the coin? Why?
Answer:
a) The coin falls in to the glass. It is due to the inertia of rest of the coin.

Question 9.
Raju placed a pencil in a trough of water as shown in figure.

a) Can you see a change in the position of the portion of the pencil under water?
b) Why does the ray of light coming after reflection from the pencil undergo a deviation?
Answer:
a) Yes
b) The ray of light from the immersed part of the pencil entering air from water is deviated at the surface of separation. It undergoes refraction.

Question 10.
Classify the following instances into inertia of motion and inertia of rest
a) A fan continue to rotate for a while even after it is switched off.
b) It is possible to strike out a single carrom coin without disturbing others, from a set of coins stacked one over the other.
Answer:
a-Inertia of motion
b-Inertia of rest

Question 11.
Write some traffic rules for pedestrians to follow.
Answer:

• Pedestrians should walk along the right side of the road.
• Cross the road only at the zebra crossing, obeying the traffic signal.
• Use sidewalks.
• Avoid crossing between parked cars.

Question 12.
A car starting from rest travels 100 m in 5 s with uniform acceleration. Find the acceleration of the car?
Answer:
u = 0 m/s
t = 5s
s = 100 m
a = ?
s = ut + \(\frac { 1 }{ 2 }\)at²
100 = 0 × 5 + \(\frac { 1 }{ 2 }\) × a × 5²
a = \(\frac{100 \times 2}{25}\) = 8 m/s²

Question 13.
State true or false.
a) The value of g will be the same everywhere on the earth.
b) The factors that influence the value of g are mass of the earth and radius of the earth.
Answer:
a) False
b) True

III. Answer any five questions from 14 to 19. (3 score each) (5 × 3 = 15)

Question 14.
The velocity-time graph of an object in straight line motion is given.

Identify the regions of the graph where the object is moving with:
a) acceleration.
b) uniform velocity.
c) deceleration.
Answer:
a) Region OA
b) Region AB
c) Region BC

Question 15.
The figure shows the motion of an object along a circular path.

a) What do you mean by uniform circular motion?
b) Write any one example for uniform circular motion.
c) If this object loses centripetal force at the point A while in circular motion, draw the path of its movement.
Answer:
a) If the object swept equal distance at equal intervals of time in a circular path it is uniform circular motion.
b) The earth revolves around the sun.
c)

Question 16.
A car moving with uniform acceleration and changes its velocity from 10 m/s to 50 m/s in 4 seconds, then
a) Find out the acceleration of car?
b) Find out the displacement in this time?
Answer:
a) a = \(\frac { v-u }{ t }\)
t = 4s
a = \(\frac{50-10}{4}\)
a = 10 m/s²

b) s = ut + \(\frac { 1 }{ 2 }\) at²
= 10 × 4 + \(\frac { 1 }{ 2 }\)(10 × 4²)
= 40 + 80
= 120 m

Question 17.
Observe the figure. A ray of light enters from medium 1 to medium 2

a) Find out which medium has greater optical density.
b) Which medium has the greater refractive index?
c) What is the relation between optical density and refractive index of a medium?
Answer:
a) Medium-1
b) Medium-1
c) As the refractive index of a medium increases, optical density also increases.

Question 18.
State true or false.
a) All internal forces are unbalanced forces.
b) All internal forces are balanced forces.
c) All balanced forces are internal forces.
Answer:
a) False
b) True
c) False

Question 19.
Differentiate between mass and weight.
Answer:
Table

IV. Answer any two questions from 20 to 22. (4 score each) (2 × 4 = 8)

Question 20.
The path of light through different media is shown in the following figure. Analyse them and answer the following questions.

a) Find out critical angle of glass.
b) Which figure represents the total internal reflection?
c) Explain how total internal reflection takes place in glass by referring the above figures.
Answer:
a) 42°
b) R
c) When a ray of light passes from a medium of higher optical density (glass) to a medium of lower optical density (air) at an angle of incidence greater than the critical angle, the ray is reflected back to the same medium without undergoing refraction. This is total internal reflection.

Question 21.
Observe the figure. A, B, C are three positions on the surface of the earth and D is the centre of the earth.

a) Is the value of mass or weight of an object is same at all positions on the surface of the earth.
b) What is the weight of an object at D?
c) On the surface of the earth at which positions among A, B and C the value of acceleration due to gravity be maximum. Justify your answer.
Answer:
a) Mass of an object is same at all positions on the surface of the earth but weight of the object varies.

b) Zero

c) Value of acceleration due to gravity is – maximum at A. Acceleration due to gravity, ‘g’ depends on the radius of the earth. As the radius decreases ‘g’ increases. The distance to A (Pole) is less than that of other positions.

Question 22.
“A man jumps from a boat to the shore”
a) Identify the action and reaction in the above situation.
b) State the law related to the given situation.
c) Write another example related to this law.
Answer:
a) Action – The boat moves backward. Reaction – The man lands on the shore.

b) Newton’s third law of motion.
The law states that for every action there is an equal and opposite reaction.

c) Recoil of a gun
Rowing a boat