Question

On what condition does an echo take place?

Answer 1

Answer:

There has to be a minimum 0.1 second of interval between the actual sound and the echo or 17 m distance between the listener and reflecting surface

Answer 2

Answer:

hope it helps ...

Explanation:

when In room we keep many things like bed ,almirah,table,etc. and when we remove these things

then echo takes place (or in simple words we can say that ) when air in conjested area comes out then echoes take place ex- in Hills we scream the echoes is forming ...