The production of echo is due to

Production of beat is due to

The principle of echo is used in ____ ultrasonography.

The production of characteristic X-rays is due to-

The production of characteristic X-rays is due to-

An echo is heard after 5 seconds of the production of sound which moves with a speed of 340 m/s. What is the distance of the mountain from the source of sound which produced the echo?

The phenomenon of echo is an example of

The phenomenon of echo is an example of