# Class 9 Science MCQ Chapter 12 Sound

Class 9 Science MCQ Chapter 12 Sound, Class 9 Science MCQ Question Answer, Class 9 Science Multiple Choice Question Answer to each chapter is provided in the list of SCERT Science Class 9 Objective Types Question Answer so that you can easily browse through different chapters and select needs one. Class 9 Science MCQ Chapter 12 Sound Question Answer can be of great value to excel in the examination.

## SCERT Class 9 Science MCQ Chapter 12 Sound

SCERT Class 9 Science MCQ Chapter 12 Sound Notes covers all the exercise questions in SCERT Science Textbooks. The NCERT Class 9 Science MCQ Chapter 12 Sound provided here ensures a smooth and easy understanding of all the concepts. Understand the concepts behind every chapter and score well in the board exams.

Sound

Chapter – 12

### Multiple Choice Questions & Answers

1. Sound can not travel through –

(a) air

(b) water

(c) steel

(d) vacuum

Ans: (d) vacuum.

2. Sound is a –

(a) potential wave

(b) kinetic wave

(c) mechanical wave

(d) none of the above

Ans: (c) mechanical wave.

3. A peak is called –

(a) trough

(b) crest

(c) wavelength

(d) frequency

Ans: (b) crest.

4. A valley is called the –

(a) frough

(b) crest

(c) wavelength

(d) frequency

Ans: (a) frough.

5. What is the S. I. unit of frequency?

(a) Hz

(b) Second

(c) metre

(d) S

Ans: (a) Hz.

6. What is S. I. unit wavelength?

(a) Hz

(b) second

(c) metre

(d) fout

Ans: (c) metre.

7. Which of the following is correct?

(a) wavelength = speed × frequency

(b) speed = wavelength × frequency

(c) frequency = speed × wavelength

(d) none of the above

Ans (b) speed wavelength × frequency.

8. A sound wave has a frequency of 2000 Hz and wave length 0.35 metre. What is the speed of sound wave?

(a) 700m/s

(b) 70m/s

(c) 7m/s

(d) 0.7m/s

Ans: (a) 700m/s.

9. At 0.c, the speed of sound in air is –

(a) 330ms⁻¹

(b) 331ms⁻¹

(c) 334ms⁻¹

(d) 344ˢ⁻¹

Ans: (b) 331ms⁻¹

10. At 22°c, the speed of sound in air is

(a) 330ms⁻¹

(b) 331ms⁻¹

(c) 334ms⁻¹

(d) 344ms⁻¹

Ans: (d) 344ms⁻¹

11. At 25°c, the speed of sound in is water –

(a) 4700ms⁻¹

(b) 3980ms⁻¹

(c) 1531ms⁻¹

(d) 1498ms⁻¹

Ans: (c) 1531ms⁻¹

12. The sensation of sound persists in our brain for about-

(a) 0.1 second

(b) 0.2 second

(c) 0.3 second

(d) 0.4 second

Ans: (a) 0.1 second.

13. The minimum distance for hearing dis. tinct echos from the source is –

(a) 17.0 m

(b) 17.2 m

(c) 17.3 m

(d) 17.4 m

Ans: (b) 17.2 m

14. Which of the following is not musical instrument?

(a) frumpets

(b) shehanais

(c) horms

(d) stethocope

Ans: (d) Stethocope.

15. Which of the following is medical instrument?

(a) Stethoscope

(b) hornes

(c) trumpets

(d) shehanais

Ans: (a) Stethoscope.

16. The audible range of sound for human beings extends from about

(a) 10Hz to 2000Hz

(b) 20Hz to 20000Hz

(c) 10Hz to 2000Hz

(d) 20Hz to 2000Hz

Ans: (b) 20Hz to 20000Hz

17. Which of the following is correct?

(a) 1Hz=4cycle/s

(b) 1Hz=3cycles

(c) 1Hz=2cycle/s

(d) 1Hz=1cycle/s

Ans: (d) 1Hz-1cycle/s.

18. Which of following animal can hear a sound of the frequency upto 25000Hz?

(a) above 18 years old man

(b) above 14 years old

(c) above the age of 7 years old children

(d) under the age of 5 years children

Ans: (d) under the age of 5 years children.

19. Rhinoceroces communicate using infrasound of frequency as low as –

(a) 7Hz

(b) 6Hz

(c) 5Hz

(d) 4Hz

Ans: (c) 5Hz.

20. Which of the following can hear high frequency squeaks of the bat?

(a) rat

(b) ant

(c) moth

(d) lizard

Ans: (c) moth

21. Infrasound can be produced by –

(a) whales

(b) dolphins

(c) bats

(d) porpoise

Ans: (a) whales.

22. Which of the following animal play games by producing ultrasound?

(a) dolphine

(b) elephant

(c) bats

(d) rats

Ans: (d) rats.

#### Very Short Answer Type Questions

1. What is called medium?

Ans: The matter or substance through which sound is transmitted is called medium.

2. Give an example of wave.

Ans: Sound.

3. What is the most common medium through which sound travels?

Ans: air.

4. What is called crest of wave?

Ans: A peak is called crest of wave?

5. What is called trough of a wave?

Ans: A valley is called the trough of wave.

6. What do you mean by compression?

Ans: The maximum pressure in a area is called compresion.

7. What do you mean by rarefactions?

Ans: The minimum pressure in a area is called rarefaction.

8. What is sound wave?

Ans: Sound is a mechanical wave.

9. What is called longitudinal wave?

Ans: The individual particles of the medium move in a direction parallel to the direction of propagation of the disturbance. It is called longitudinal wave.

10. Give an example of longitudinal wave?

Ans: Sound wave.

11. What is called transverse wave?

Ans: Particles up and down about their mean position as the wave trakets. This wave is called transverse wave.

12. Give an example of transverse wave.

Ans: light.

13. Give an example of wave which is not mechanical wave?

Ans: light.

14. What is called wavelength?

Ans: The distance between two consecutive compressions or two consecutive rarefactions is called the wavelength.

15. What is the S. I. unit of wavelength?

Ans: metre.

16. What is the Symbol of wavelength?

Ans:

17. What is called time period?

Ans: The time taken for one complete Oscillation in the density of the medium is called the time period.

18. What is the S.I. unit of time period?

Ans: Second.

19. What is the S.I. unit of frequency?

Ans: Hz (Hertz)

20. Time period (T) and frequency (v), What is the relation between them?

1

Ans: v= ——

T

21. What is called pitch?

Ans: The brain interprets the frequency of an emitted sound is called pitch.

22. What is called amplitude of the wave?

Ans: The magnitude of the maximum disturbance in the medium on the either side of the mean value is called the amplitude of the wave.

23. What is called tone?

Ans: A sound of single frequency is called a tone.

24. What is called note?

Ans: The sound which is produced due to a mixture of several frequencies is called note.

25. What is the difference between note and noise?

Ans: Note is pleasant to listen to and noise is unpleasant to ear.

26. What is th speed of sound at 25°c is Oxygen?

Ans: 316 ms⁻¹

27. What is called echo?

Ans: Shout or clap a suitable reflecting object such as a tall building or a mountain, after a little time, the sound can hear again. It is called echo.

28. Write the name of an instrument which is used multiple reflection of sound?

Ans: Megaphones.

29. Write the name of an instrument which is used for listening sound of lungs and heartbeat.

Ans: Stethoscope.

30. What is called ultrasonic sound?

Ans: Frequencies higher than 20KHz are called ultrasonic sound or ultra sound.

31. What is called infrasonic sound?

Ans: Sound of frequencies below 20 Hz are called infrasonic sound or infrasound.

32. Write the three bones is the ear.

Ans: hammer, anvil and stirrup.

33. What is called pinna?

Ans: The outer ear is called pinna.

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