SSC Selection Post 2022 PYQ — Question 40

The correct answer is option 2 i.e. sonar. 

An apparatus used only for receiving the sounds generated by underwater objects is called a passive sonar system.

Sonar, which stands for Sound Navigation And Ranging, is a technology that uses sound propagation to navigate, communicate with, or detect objects on or under the surface of the water. There are two main types: active sonar and passive sonar.

Passive sonar systems are designed to simply listen for the sounds produced by underwater objects, such as ships, submarines, marine animals, or geological activities. Unlike active sonar, passive sonar does not emit its own sound pulses. This "listening-only" characteristic makes passive sonar invaluable for stealth applications, as it allows a vessel to detect other objects without revealing its own presence.