Class 9 Practice Level 3 – Sound set – 1

Total questions: 15

If the sound intensity at a distance of 2 meters from a source is 80 dB, what will be the intensity at a distance of 8 meters from the source?

Topic: Sound Intensity

74 dB

68 dB

62 dB

56 dB

None

A sound wave travels 1700 meters in 5 seconds in a certain medium. What is the speed of sound in that medium?

Topic: Speed of Sound

340 m/s

300 m/s

370 m/s

400 m/s

None

A sound wave has a frequency of 500 Hz and a wavelength of 0.68 meters. What is the speed of sound in the medium?

Topic: Frequency and Wavelength

300 m/s

340 m/s

360 m/s

400 m/s

None

A train sounding its whistle at a frequency of 600 Hz approaches a stationary observer at a speed of 25 m/s. If the speed of sound is 340 m/s, what frequency does the observer hear?

Topic: Doppler Effect

615 Hz

645 Hz

675 Hz

705 Hz

None

A pipe closed at one end has a length of 0.85 meters. If the speed of sound is 340 m/s, what is the fundamental frequency of the pipe?

Topic: Harmonics

50 Hz

100 Hz

150 Hz

200 Hz

None

If the sound pressure level increases from 80 dB to 90 dB, by what factor does the sound pressure increase?

Topic: Sound Pressure

1.5

None

Two tuning forks of frequencies 256 Hz and 260 Hz are sounded together. What is the beat frequency?

Topic: Beats

2 Hz

4 Hz

6 Hz

8 Hz

None

A sound wave is reflected off a wall and returns to the source in 2 seconds. If the speed of sound is 340 m/s, how far is the wall from the source?

Topic: Sound Reflection

170 meters

340 meters

510 meters

680 meters

None

If two sounds have intensity levels of 70 dB and 80 dB respectively, what is the combined intensity level?

Topic: Sound Intensity

75 dB

62 dB

80 dB

90 dB

None

10.

A sound wave has an amplitude of 0.02 meters and a frequency of 200 Hz. What is the maximum speed of the particles of the medium through which the sound is traveling? (Assume the speed of sound in the medium is 340 m/s)

Topic: Sound Wave Properties

4 m/s

8 m/s

12 m/s

16 m/s

None

11.

A tuning fork resonates with an air column of length 0.75 meters. If the speed of sound is 340 m/s, what is the frequency of the tuning fork?

Topic: Acoustic Resonance

113 Hz

226 Hz

453 Hz

906 Hz

None

12.

Two sound waves of amplitudes 3 units and 4 units interfere constructively. What is the resulting amplitude?

Topic: Wave Interference

1 unit

5 units

7 units

12 units

None

13.

An ambulance moving at 20 m/s emits a siren sound at a frequency of 800 Hz. What frequency does a stationary observer hear as the ambulance approaches? (Speed of sound = 340 m/s)

Topic: Doppler Effect

850 Hz

875 Hz

900 Hz

925 Hz

None

14.

A sonar device on a submarine sends out a signal and receives an echo 5 seconds later. If the speed of sound in water is 1500 m/s, what is the distance to the object?

Topic: Echo

3750 meters

4500 meters

6000 meters

7500 meters

None

15.

A vibrating string has a fundamental frequency of 220 Hz. What is the frequency of its second overtone?

Topic: Harmonics

220 Hz

440 Hz

660 Hz

880 Hz

None

1 out of 15

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Class 9 Practice Level 3 – Sound set – 1

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