Question

4 एक्स माइनस 3 अपऑन 5 माइनस 5 एक्स माइनस 3 अपॉन 8 इज इक्वल टू वन ​

Answer 1

The applications of echo:

Dolphins detect their enemy and obstacles by emitting the ultrasonic waves and hearing their echo.

In medical science, the echo method of ultrasonic waves is used for imaging the human organs such as the liver, gall bladder, uterus, womb etc. This is called ultrasonography.