10th class Physics, Chapter 13: Sound MCQs

1. What is required for the production of sound?

1. (A) A vacuum
2. (B) Vibrations of a medium ✓
3. (C) Only air
4. (D) Light waves

2. An echo is produced due to:

1. (A) refraction of sound waves
2. (B) reflection of sound waves ✓
3. (C) diffraction of sound waves
4. (D) absorption of sound waves

3. An example of a longitudinal wave is:

1. (A) light wave
2. (B) water wave
3. (C) sound wave ✓
4. (D) radiowave

4. In which medium does sound travel the fastest?

1. (A) Gases
2. (B) Liquids
3. (C) Solids ✓
4. (D) Vacuum

5. What is the approximate speed of sound in air?

1. (A) 150 m s⁻¹
2. (B) 330-350 m s⁻¹ ✓
3. (C) 500 m s⁻¹
4. (D) 1,000 m s⁻¹

6. Why is acoustic protection important in building design?

1. (A) To increase noise pollution
2. (B) To reduce echo and improve sound quality ✓
3. (C) To amplify sound
4. (D) To increase the speed of sound

7. For a normal person, the audible frequency range for sound waves lies between:

1. (A) 10 Hz and 10 kHz
2. (B) 20 Hz and 20 kHz ✓
3. (C) 25 Hz and 25 kHz
4. (D) 30 Hz and 30 kHz

8. Sound is produced by:

1. (A) light
2. (B) vibrating objects ✓
3. (C) stationary objects
4. (D) objects at rest in a vacuum

9. When a vibrating tuning fork touches a hanging table-tennis ball, the ball:

1. (A) stays at rest
2. (B) sticks to the fork
3. (C) becomes heavier
4. (D) moves away, showing the fork is vibrating ✓

10. Sound cannot travel through:

1. (A) water
2. (B) steel
3. (C) air
4. (D) a vacuum ✓

11. Sound is a mechanical wave, so it:

1. (A) is an electromagnetic wave
2. (B) requires a medium ✓
3. (C) can travel through a vacuum
4. (D) travels at the speed of light

12. In the bell jar experiment, as the air is pumped out the sound of the bell:

1. (A) becomes louder
2. (B) does not change
3. (C) changes its pitch
4. (D) becomes weaker and fades ✓

13. In a sound wave the particles of air move:

1. (A) at right angles to the wave
2. (B) in a circle
3. (C) along with the wave to the listener
4. (D) back and forth along the direction of the wave ✓

14. Sound travels about ____ times faster in solids than in gases.

1. (A) 15 ✓
2. (B) 5
3. (C) 2
4. (D) 100

15. According to the book, the speed of sound in air at room temperature (21 °C) is:

1. (A) 391 m s⁻¹
2. (B) 1498 m s⁻¹
3. (C) 343 m s⁻¹ ✓
4. (D) 330 m s⁻¹

16. The speed of sound in air increases when the:

1. (A) amplitude falls
2. (B) temperature rises ✓
3. (C) temperature falls
4. (D) frequency falls

17. According to Table 13.1, the speed of sound in distilled water at 25 °C is:

1. (A) 1498 m s⁻¹ ✓
2. (B) 330 m s⁻¹
3. (C) 5960 m s⁻¹
4. (D) 200 m s⁻¹

18. Which medium in Table 13.1 has the highest speed of sound?

1. (A) Steel
2. (B) Sea water
3. (C) Helium
4. (D) Aluminium ✓

19. In which of these gases is the speed of sound (0 °C) the highest, according to Table 13.1?

1. (A) Helium
2. (B) Air
3. (C) Hydrogen ✓
4. (D) Oxygen

20. The speed of sound in sea water (25 °C) is about:

1. (A) 5000 m s⁻¹
2. (B) 3 × 10⁸ m s⁻¹
3. (C) 1531 m s⁻¹ ✓
4. (D) 331 m s⁻¹