ANSWERS 143
Chapter 13
MULTIPLE CHOICE QUESTIONS
1. b 2. a 3. d 4. a
5. c 6. a 7. a 8. c
9. a 10. c
V ERY SHORT ANSWER Q UESTIONS
11. 1650 m
12. Yes, larynx (vocal cords)
13. The speed of sound is lower than that of the speed of light and
therefore sound reaches him later than light.
14. Yes, eardrum.
15. Sitar and Ektara (any other musical instruments which produces
sound by a vibrating string)
S HORT ANSWER QUESTIONS
16. Time period : 2 s
frequency : 0.5 oscillations/sec
17. If the sound produced by a vibrating body is in the audible range,
the sound produced will be heard by us otherwise we will not be
able to hear the sound even though the body is vibrating.
18. The frying pan will vibrate. We will not be able to hear the sound
of vibration because sound cannot travel in vacuum.
19. No, In space there is vacuum and sound cannot travel in vacuum.
20. Vehicle noise, bursting of crackers, loudspeakers.
(Any other reasonable sources of noise pollution should be
accepted)
Chapter 13
MULTIPLE CHOICE QUESTIONS
1. b 2. a 3. d 4. a
5. c 6. a 7. a 8. c
9. a 10. c
V ERY SHORT ANSWER Q UESTIONS
11. 1650 m
12. Yes, larynx (vocal cords)
13. The speed of sound is lower than that of the speed of light and
therefore sound reaches him later than light.
14. Yes, eardrum.
15. Sitar and Ektara (any other musical instruments which produces
sound by a vibrating string)
S HORT ANSWER QUESTIONS
16. Time period : 2 s
frequency : 0.5 oscillations/sec
17. If the sound produced by a vibrating body is in the audible range,
the sound produced will be heard by us otherwise we will not be
able to hear the sound even though the body is vibrating.
18. The frying pan will vibrate. We will not be able to hear the sound
of vibration because sound cannot travel in vacuum.
19. No, In space there is vacuum and sound cannot travel in vacuum.
20. Vehicle noise, bursting of crackers, loudspeakers.
(Any other reasonable sources of noise pollution should be
accepted)
