# Waves of Sound

## Trending Questions

**Q.**

A man is standing between two parallel cliffs and fires a gun. If he hears first and second echoes after 1.5 s and 3.5 s respectively, the distance between the cliffs is (Velocity of sound in air = 340 ms−1)

1190

*m*850

*m*595

*m*510

*m*

**Q.**When two sound waves with a phase difference of π2, and each having amplitude A and frequency ω, are superimposed on each other, then the amplitude and frequency of resultant wave is

**Q.**

A listener moves towards stationary sound source with a constant speed and crosses it then the correct graph between Apparent frequency with time is please explain

**Q.**

Where does maximum constructive interference occur?

**Q.**

A stone is dropped from a 500 m tall building into a pond. When is sound of splash heard after the dropping of the stone? g = 10 m/s2, speed of sound = 340 m/s

10 s

1.47 s

11.47 s

immediately (at t = 0)

**Q.**

The speed of a wave is $340m{s}^{-1}$. What is the wavelength of the wave if its frequency is 500 Hz?

0.68 m

6.8 m

68 m

0.68 cm

**Q.**When sound wave is refracted from air to water, which of the following will remain unchanged?

Wave number

Wavelength

Wavevelocity

Frequency

**Q.**A stone is dropped from the top of a tower of 500 m height, into a pond of water at the base of the tower. When is the splash heard at the top?

(Given g=10 ms−2 and speed of sound =340 ms−1)

- 10 s
- 11.47 s
- 1.10 s
- 20 s

**Q.**A block of mass 1 kg attached to a spring is made to oscillate with an initial amplitude of 12 cm. After 2 minutes the amplitude decreases to 6 cm. Determine the value of the damping constant for this motion. (take ln2=0.693).

- 0.69×102 kg s−1
- 3.3×102 kg s−1
- 5.7×10−3 kg s−1
- 1.16×10−2 kg s−1

**Q.**A road runs midway between two parallel rows of buildings. A motorist moving with a speed of 36km/hour sounds the horn. He hears the echo one second after he has sounded the horn. The distance between the 2 rows of buildings is (Velocity of sound is 330m/s)

- 300m
- 150m
- 1080m
- 330m

**Q.**

A man is standing in a valley between two parallel mountains. He fires a gun and hears echo at an interval of 2s and 3.5s. what is the distance between 2 mountains? (Take speed of sound = 350 m/s)

350 m

700 m

612.5 m

962.5 m

**Q.**

An organ pipe ${P}_{1}$ closed at one end and vibrating in its first overtone pipe ${P}_{2}$ open at both ends vibrating in its third overtone are in resonance with a given tuning fork. The ratio of the lengths of ${P}_{1}$ to that of ${P}_{2}$ is?

**Q.**If the medium changes, for the same wave the frequency remain the same but the speed changes because the wave speed apart of frequency also depends upon:

- Frequency
- Wavelength
- Amplitude
- All of them

**Q.**A man is standing between two parallel cliffs and fires a gun. If he hears first and second echoes after 1.5 s and 3.5 s respectively, the distance between the cliffs is (Velocity of sound in air = 340 ms−1)

- 1190 m
- 850 m
- 595 m
- 510 m

**Q.**A sound wave of frequency 100 Hz is travelling in air. The speed of sound in air is 350 m s−1. By how much is the phase changed at a given point in 2.5 ms?

**Q.**A man is standing between two parallel cliffs and fires a gun. If he hears the echoes after 1.5s and 3.5s respectively, the distance between the cliffs is (velocity of sound in air = 340m/s)

- 1190m
- 850m
- 595m
- 510m

**Q.**A wave passes from one minimum to another medium. Mention the property of the wave

which changes

which does not change.

**Q.**

If in a medium wave's wavelength is decreased, what will happen to its frequency?

Decrease

Increase

Data insufficient need density too

Frequency Doesn't depend on wavelength

**Q.**

A man is standing in a valley between two parallel mountains. He fires a gun and hears echo at an interval of 2s and 3.5s. what is the distance between 2 mountains? (Take speed of sound = 350 m/s)

350 m

700 m

962.5 m

612.5 m

**Q.**A person places his ear at the end of a long steel pipe. He hears two distinct sounds at an interval of 0.5 s when another person hammers at the other end of the pipe. If the speed of the sound in metal and air are 3630 ms−1 and 330 ms−1 respectively, then the distance between the two persons is

- 90.75 m
- 181.5 m
- 363 m
- 1650 m

**Q.**A stone is dropped into a lake from a tower 500m high. The sound of the splash will be heard by a man on the tower after a time of (velocity of sound in air=350 m/s)

- 21s
- 10s
- 11.4s
- 1s

**Q.**The splash is heard after 2.05s after the stone is dropped into a well of depth 19.6m the velocity of sound is:

- 342ms−1
- 372ms−1
- 392ms−1
- 352−1

**Q.**

A stone is dropped into a lake from a tower 500 metre high. Taking the speed of sound as 330 m/s, the sound of the splash will be heard by the man approximately after

11.5 seconds

21 seconds

10 seconds

14 seconds

**Q.**

A stone is dropped into a lake from a tower 500 metre high. Taking the speed of sound as 330 m/s, the sound of the splash will be heard by the man approximately after

11.5 seconds

10 seconds

14 seconds

21 seconds

**Q.**Sound waves can diffract easily because

- Their wavelength is very small
- Their wavelength is large
- It can refract
- It can reflect

**Q.**

If in a medium wave's wavelength is decreased, what will happen to its frequency?

Increase

Decrease

Frequency Doesn't depend on wavelength

Data insufficient need density too

**Q.**A man is driving a car at a speed of 72 kmph towards a hill. He sounds the horn and hears its echo after 2 seconds. At what distance from the hill the horn was sounded. (Velocity of sound = 340 m/s)

- 420 m
- 390 m
- 340 m
- 260 m

**Q.**A source of the sound of frequency 90 vibrations/sec is approaching a stationary observer with a speed equal to 1/10 the speed of sound. What will be the frequency heard by the observer

- 80vibrations/sec
- 120vibrations/sec
- 90vibrations/sec
- 100vibrations/sec

**Q.**When sound wave is refracted from air to water, which of the following will remain unchanged?

(a) Wave number

(b) Wavelength

(c) Wave velocity

(d) Frequency

**Q.**

A stone is dropped from a 500 m tall building into a pond. When is sound of splash heard after the dropping of the stone? g = 10 m/s2, speed of sound = 340 m/s

10 s

1.47 s

11.47 s

immediately (at t = 0)