Question

An echo cannot be heard in a small room whereas it can be heard in a large empty room. Give reason.​

Answer 1

Answer:

Echo is heard when the sound gets reflected back. In an empty room, the sound is reflected by the walls so the echo is heard. But in a living room there are so many sound absorbers present like curtains, furniture etc. They absorb sound instead of reflecting them and thus reduces the possibility of echo in the room.

Answer 2

Answer:

A sound endures in our ear for 0.1s . At temperature 22∘C in air and speed of sound 344ms−1 , the absolute distance covered by strong between the place of age and reflecting surface ought to be in any event (344m/s)×0.1s=34.4m . Accordingly, the base distance between the place of age and reflecting surface ought to be half of it for example 17.2m .

Explanation:

In this way, we can't hear a reverberation in a little room as the base distance for the reverberation won't be fulfilled. Yet, we can hear a reverberation in a long exhibition and enormous lobbies.