EASY

Earn 100

State two laws of reflection of sound.

Important Questions on Sound

EASY

Science>Physics>Sound>Reflection of Sound

Sound travels at a speed of

1450 {ms}^{- 1}

through water. A submarine detects objects around it by sending sound waves and detecting echo (reflected sound) heard after

4 s

. Then the object must be at a distance of:

EASY

Science>Physics>Sound>Reflection of Sound

If the velocity of sound in air is

340 m s^{- 1}

and

x

is the minimum distance between sound source and reflecting surface to get echo from general sound, then :

EASY

Science>Physics>Sound>Reflection of Sound

A person clapped his hands near a cliff and heard the echo after $4 s$ . The distance between the cliff and the person will be :

(Speed of sound is $346 m s^{- 1}$ )

MEDIUM

Science>Physics>Sound>Reflection of Sound

Name the system which enables us to locate underwater objects by transmitting ultrasonic waves and detecting the reflecting impulse.

EASY

Science>Physics>Sound>Reflection of Sound

What is the difference between reverberation and echo?

EASY

Science>Physics>Sound>Reflection of Sound

What is the minimum distance required to hear an echo in air?

EASY

Science>Physics>Sound>Reflection of Sound

A girl drops a ball from a height

h = 20 m

. It strikes the ground elastically and returns to her hand. An echo of the thud of the ball striking the ground is produced from a nearby cliff. The echo is head at exactly the same moment when the ball returns to the girl's hand. (Take g =

10 {ms}^{- 2}

and

v_{sound} = 350 {ms}^{- 1}

). The distance of the cliff from the girls is close to:

EASY

Science>Physics>Sound>Reflection of Sound

Sound signal from a ship floating in water hits the bottom of the sea and reflects back to the ship after

6 s

. Speed of sound in water is

1500 m s^{- 1}

. Calculate the depth of the sea.

EASY

Science>Physics>Sound>Reflection of Sound

A man who is standing at a distance of

850 m

from a sound reflecting surface claps loudly. If the velocity of the sound in air is

340 {ms}^{- 1}

then the time taken by the echo to reach him is

HARD

Science>Physics>Sound>Reflection of Sound

A pendulum has a frequency of

4

vibrations per second. An observer starts the pendulum and fires a gun simultaneously. He hears the echo from the cliff after

6

vibrations of the pendulum. If the velocity of sound in air is

340 {ms}^{- 1}

, find the distance between the cliff and the observer.

EASY

Science>Physics>Sound>Reflection of Sound

How long does sound persist in our ears?

EASY

Science>Physics>Sound>Reflection of Sound

A person clapped hands near a wall and heard the echoes after

5 s

. What is the distance of the wall from the person, if the speed of the sound at that time was

346 \frac{m}{s}

EASY

Science>Physics>Sound>Reflection of Sound

An echo is heard

0.6 s

after a person bursts a cracker at a distance of

102 m

from a high building. Calculate the speed of the sound.

EASY

Science>Physics>Sound>Reflection of Sound

Why do we not hear echo at all places?

MEDIUM

Science>Physics>Sound>Reflection of Sound

What is meant by an echo? How is it heard? Explain the various conditions necessary for the formation of echoes.

EASY

Science>Physics>Sound>Reflection of Sound

What is meant by reflection of sound?

EASY

Science>Physics>Sound>Reflection of Sound

For doing the experiment on the verification of laws of reflection of sound,

MEDIUM

Science>Physics>Sound>Reflection of Sound

While doing an experiment on verifying the laws of reflection of sound, four students measured the angles $∠ i$ and $∠ r$ as shown in the diagram below. The correct measurement of the angles of incidence and angles of reflection has been done by which student?

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