Question

list two principles of SONAR​

Answer 1

Both radar and sonar locate objects from the echo of a signal that is bounced off the object. Radar uses radio waves, which are a type of electromagnetic energy. Sonar uses the echo principle by sending out sound waves underwater or through the human body to locate objects. Sound waves are a type of acoustic energy.

Answer 2

$\huge\bold{SONAR:}$

=> It stands for Sound Navigation And Ranging.

=> It is a device or in other words an apparatus which is basically used to find the depth of the water bodies mainly ocean or seas and or is used to locate the things shipwrecks, (enemy) submarines, etc found under the water.

=> It consists of two parts mainly called :

i. A transmitter (which is used for emitting the ultrasonic waves)
ii. A receiver (basically used for detecting the ultrasonic waves)

$\huge\bold{How\:it\:works\:?}$

SONAR basically works by sending really short bursts of ultrasonic sound mainly from ships down under sea water and then picking up the echo which is produced by the reflection of the ultrasonic sound from objects under sea water like the bottom part or the sea bed, shipwreck, or the submarine, etc.

$\huge\bold{Extras:}$

The time taken for the echo to return back to the ship is mainly measured by the SONAR device/apparatus. The range or the distance of the object under water is by then calculated from the time taken by the echo to return back to it.

Thus, the time it takes for an echo to return is basically used to find out how far away something (object) is.

$\large\bold{NOTE :}$ The speed of the ultrasonic sound under the water is same as that of the ordinary sound.