Solved Sample Paper 4 — Question 21

Yes, SONAR is used for determining the depth of the sea.

To find the depth of the sea, the time interval (t) between the instant when waves are sent and the instant when waves are received, after reflection from the depth is measured.

The depth d of the sea is then —

$\text{d} = \dfrac{Vt}{2} \\[0.5em]$

where, V is the speed of ultrasonic wave in water.

This process is called echo depth sounding.