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

Question

Question

This question was previously asked in

SSC HSC Level Previous Paper (Held on: 9 Feb 2022 Shift 2)

Answer 1

The correct answer is sonar.

Key Points

Sonar is a technique that uses sound propagation to navigate, measure distances, and communicate with or detect objects on or under the surface of the water, such as other vessels.
SONAR stands for "Sound Navigation and Ranging".
Sound waves emitted by or reflected from the object are detected by sonar apparatus and analyzed for the information they contain.
Scientists primarily use sonar to develop nautical charts, locate underwater hazards to navigation, search for and map objects on the seafloor such as shipwrecks, and map the seafloor itself. There are two types of sonar—active and passive.

Additional Information

Name of the Instrument	Functions/ Used for
Barometer	Measuring atmospheric pressure.
Galvanometer	Measuring small electric current.
Ammeter	Measuring the strength of the electric current.
Pyrometer	Measuring very high temperature.
Calorimeter	Measuring quantities of heat.
Polygraph	Recording changes, simultaneously in physiological processes such as heartbeat, blood pressure, and respiration also used as a lie detector.
Electrocardiograph (ECG)	Measuring movements of the heart.
Dynamo	Converts mechanical energy into electrical energy.
Periscope	Used for viewing objects above sea level.
Electroencephalograph (EEG)	Measures electrical activities in the brain.