Class 9 Practice Level 3 - Sound - Set 2

Total questions: 15

The speed of sound in a medium is 400 m/s, and its wavelength is 2 meters. What is the frequency of the sound wave?

Topic: Sound Wave Properties

100 Hz

200 Hz

300 Hz

400 Hz

None

A string fixed at both ends has a length of 1 meter and a speed of 340 m/s. What is the frequency of its first overtone?

Topic: Resonance

170 Hz

340 Hz

510 Hz

680 Hz

None

If the sound pressure level is 90 dB, what is the sound pressure (in Pascals) if the reference pressure is $ \displaystyle 2\times {{10}^{{-5}}}\text{ Pa}?$

Topic: Sound Pressure Level

0.02 Pa

0.2 Pa

2 Pa

20 Pa

None

If two sound waves with frequencies of 500 Hz and 510 Hz are played together, what is the beat frequency?

Topic: Beats

5 Hz

10 Hz

15 Hz

20 Hz

None

A sound wave takes 3 seconds to travel from point A to point B and back to point A after reflection. If the speed of sound in the medium is 300 m/s, what is the distance between point A and point B?

Topic: Sound Reflection

225 meters

450 meters

675 meters

900 meters

None

A sound wave has a frequency of 850 Hz and a wavelength of 0.4 meters. What is the speed of sound in the medium?

Topic: Frequency and Wavelength

320 m/s

340 m/s

360 m/s

380 m/s

None

A sound wave is reflected off a wall and returns to the source in 6 seconds. If the speed of sound is 340 m/s, how far is the wall from the source?

Topic: Sound Reflection

510 meters

1020 meters

1530 meters

2040 meters

None

Two sound waves with frequencies of 530 Hz and 540 Hz are played together. What is the beat frequency?

Topic: Beats

5 Hz

10 Hz

15 Hz

20 Hz

None

A string fixed at both ends has a length of 2 meters and a fundamental frequency of 85 Hz. What is the frequency of its third harmonic?

Topic: Harmonics

170 Hz

255 Hz

340 Hz

425 Hz

None

10.

A pipe open at both ends has a length of 1.5 meters. If the speed of sound is 340 m/s, what is the fundamental frequency of the pipe?

Topic: Acoustic Resonance

56.7 Hz

113.3 Hz

226.7 Hz

340 Hz

None

11.

An observer is moving away from a stationary sound source at a speed of 15 m/s. The source emits a frequency of 400 Hz. What is the observed frequency if the speed of sound is 340 m/s?

Topic: Doppler Effect

362 Hz

375 Hz

383 Hz

390 Hz

None

12.

The sound intensity at a distance of 1 meter from a source is 90 dB. What will be the intensity level at a distance of 3 meters from the source?

Topic: Sound Intensity

80 dB

82 dB

84 dB

86 dB

None

13.

A sound wave has an amplitude of 0.03 meters and a frequency of 250 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

3 m/s

4.7 m/s

5 m/s

6 m/s

None

14.

A string fixed at both ends has a length of 1.2 meters and produces a second harmonic frequency of 200 Hz. What is the speed of the wave on the string?

Topic: Resonance

240 m/s

300 m/s

400 m/s

480 m/s

None

15.

If the sound pressure level is 100 dB, what is the sound pressure (in Pascals) if the reference pressure is $ \displaystyle 2\times {{10}^{{-5}}}\text{Pascals}?$

Topic: Sound Pressure Level

0.02 Pa

0.2 Pa

2 Pa

20 Pa

None

1 out of 15

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Class 9 Practice Level 3 - Sound - Set 2

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