7th Science Refresher Course Unit 1 Force and Motion - Answer key 2021 -2022 - English Medium

7th Science Refresher Course Unit 1 விசையும் இயக்கமும் Answer key 2021 -2022 -Tamil Medium Click HERE

EVALUATION

I. Choose the Correct Answer :

1. Unit of speed is ___________________ .

(a) m 

(b) s 

(c) m/s 

(d) kg

2. The earth rotates from _________________.

(a) East to west 

(b) West to east

(c) South to north 

(d) North to south

3. Revolution of moon around the earth is __________________.

(a) Oscillatory Motion 

(b) Curvilinear Motion

(c) Periodic Motion 

(d) Rotatory Motion

II. Complete the Analogy:

4. Kicking a ball : Contact force

Falling of leaf : _____________ Answer : Gravitation

5. Rotatory Motion : A spinning top

Oscillatory Motion : _____________ Answer : The oscillation of the individual pendulum

6. Distance : Metre

Speed : _____________ Answer : m/s 

III. Fill Ups:

7. Gravitational force is a ______________________ force.

 Answer : 

8. A vehicle moving on a straight road is an example of _________________ motion.

 Answer : 

9. People walking in a crowded street _________________ motion.

 Answer : 

10. Motion of the potter’s wheel is an example for ________________ motion.

 Answer : 

IV. Write True or False:

11. SI Unit of distance is kilometer.

 Answer : false

12. A child playing in a swing is periodic motion.

 Answer : true

13. Vehicles moving with varying speeds are said to be in uniform motion.

 Answer : false

14. Flapping of elephant’s ears is oscillatory motion.

 Answer : true

V. Match the Following :

15. The tip of hands of a clock - Non periodic motion

16. The motion of a train - Circular motion

17. Flapping of a flag in wind - Periodic motion

18. Movement of needle in a sewing machine - Rotatory motion

19. Movement of the wheel - Oscillatory motion

20. Swinging of a pendulum - Uniform motion

 Answer : 

15. The tip of hands of a clock - Circular motion

16. The motion of a train - Uniform motion

17. Flapping of a flag in wind - Non periodic motion

18. Movement of needle in a sewing machine - Periodic motion

19. Movement of the wheel -  Rotatory motion

20. Swinging of a pendulum - Oscillatory motion