Question

Expand SONAR ?
Give 2 applications

Answer 1

SONAR is originally an acronym for SOund Navigation And Ranging is a technique that uses sound propagation (usually underwater, as in Submarine navigation) to navigate, communicate with or detect other vessels.Two types of technology share the name "sonar": passive sonar is essentially listening for the sound made by vessels; active sonar is emitting pulses of sounds and listening for echoes.
USES are:
Sonar may be used as a means of acoustic location and of measurement of the echo characteristics of "targets" in the water.

Answer 2

Full form of sonar = Sound Navigation and Ranging. 

Applications :-

1. For detecting explosive dangers underwater

2. For measuring underwater things distance.