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#### First 3 Chapter Test

9th Standard

Reg.No. :
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Science

Time : 01:00:00 Hrs
Total Marks : 120

Section-A

10 x 1 = 10
1. Which among the following is not a device to measure mass

(a)

Spring balance

(b)

Beam balance

(c)

Physical balance

(d)

Digital balance

2. ____________is the fundamental quantity.

(a)

Length

(b)

Area

(c)

Volume

(d)

Density

3. Light year is the distance travelled by light________.

(a)

one year

(b)

two years

(c)

10 years

(d)

5 years

4. Slope of the velocity - time graph gives

(a)

speed

(b)

displacement

(c)

distance

(d)

acceleration

5. The force responsible for drying of clothes in a washing machine is

(a)

Centripetal force

(b)

Centrifugal force

(c)

Gravitational force

(d)

Electro static force

6. During uniform motion, the change in velocity is _______

(a)

zero

(b)

infinity

(c)

constant

(d)

one

7. The slope of the velocity time graph for uniformly accelerated motion give _____

(a)

speed

(b)

acceleration

(c)

displacement

(d)

velocity

8. Area under a velocity time graph gives ______

(a)

time taken by an object

(b)

distance travelled by an object

(c)

acceleration

(d)

retardation

9. When the reflecting surface is curved outwards the mirror formed will be

(a)

concave mirror

(b)

convex mirror

(c)

plane mirror

10. Virtual and magnified image is formed by________________________mirror

(a)

concave

(b)

convex

(c)

plane

(d)

both concave and convex

11. Section-B

5 x 1 = 5
12. Negative acceleration is called ____________

()

retardation

13. Give an example of a motion in which the displacement is zero, but the distance travelled is not zero ______

()

Circular motion

14. The mirror used in search light is ________ .

()

Concave

15. When a ray of light travels from______________________ to rarer it bends away from the normal

()

denser

16. Light has maximum speed in______________

()

Vacuum

17. Section-C

1 x 1 = 1
Mass is the amount of matter contained in an object. Measurement of mass helps us to distinguish between a lighter and a heavier body. Beam balance, spring balance and electronic balance are used to measure mass of different objects. The SI unit of mass is the kilogram (kg). But different units are used to measure the mass of different objects. E.g. weight (mass) of a tablet is measured in milligrams (mg),  weight of a student is measured in kilogram (kg) and weight of a truck with goods is measured in metric tons. 1 metric ton is equal to 10 quintals and 1 quintal is equal to 100 kg. 1 gram is equal to 1000 mg.
How will you measure the weight of a tablet?
a. kg          b. g
c. mg          d. None of these

19. Section-D

5 x 2 = 10
20. What is the full form of SI system?

21. A student takes 15 minutes to travel from his home to school with a uniform speed of 5km/h. What is the distance of his school form the home?

22. Give two examples of transparent medium that are denser than air

23. Name the spherical mirror(s) that has/have
i) Virtual principal focus
ii) Real principal focus

24. What do you conclude about the speed of light in diamond if you are told that the refractive index of diamond is 2.41?

25. Section-E

5 x 3 = 15
26. Write the rules that are followed in writing the symbols of units in SI system.

27. What are the fundamental physical quantities and their units?

28. A bus travel, a distance of 20km from Chennai central airport in 45 minutes. What is the average speed?

29. The speed of a particle is constant. Will it have acceleration? Justify with an example.

30. The diagram shows the position of a ball a it rolls down a track - the ball took 0.5s sec to roll from one position to other.
(a) State where the motion of the ball is uniform or non-uniform motion.
(b) What is the distance travelled by the ball in 2.5 s?
(c) Find the average velocity of the ball from. A to F.

31. Section-F

3 x 5 = 15
32. Inian and Ezhilan argue about the light year. Inian tells that it is 9.46 × 1015 m and Ezhilan argues that it is 9.46 × 1012 km. Who is right? Justify your answer.

33. An Athlete completes one round of a circular track of diameter 200 m in 40 s. What will be the distance covered and the displacement at the end of 2 m and 20 s?

34. State and verify laws of refraction using a glass slab

35. Section-D

2 x 2 = 4
36. Mark the correct choice as:
(a) Both assertion and reason are true and reason in the correct explanation of assertion.
(b) Both assertion and reason are true but reason is not the correct explanation of assertion.
(c) Assertion is true but reason is false.
(d) Assertion is false but reason is true.
Assertion: The accelerated motion of an object may be due to change in magnitude of velocity or direction or both of them.
Reason: Acceleration can be produced only by change in magnitude of the velocity it does not depend the direction.

37. Mark the correct choice as:
(a) Both assertion and reason are true and reason is the correct explanation of assertion.
(b) Both assertion and reason are true but reason is not the correct explanation of assertion.
(c) Assertion is true but reason is false.
(d) Assertion is false but reason is true.
Assertion: When an object moves with constant speed along a circular path, the motion is called uniform motion.
Reason: When an object is moving with a constant speed along a circular path, the velocity changes due to the change in direction.