Question

SONAR is based on the principle of
A. echo
B. resonance
C. reverberation
D. anyone of the above

Answer 1

Hint – Here to solve this problem you need to know that sonar (sound navigation ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, communicate with or detect objects on or under the surface of the water, such as other vessels.

Step-By-Step answer:
SONAR stands for Sound Navigation and Ranging and it is used to find the depth of sea and ocean. SONAR is based on the principle of echo.
Sonar is helpful for exploring and mapping the ocean because sound waves travel farther in the water than do radar and light waves. Sonar is also used in acoustic homing torpedoes, in acoustic mines, and in mine detection. Non-military uses of sonar include fish finding, depth sounding, mapping of the sea bottom, Doppler navigation, and acoustic locating for divers.
In SONAR, a sound signal is sent downwards into the sea. The sound gets reflected at the bottom of the sea and thus the reflected sound is detected as an echo and the time taken by it to come back is recorded. Since, we know the speed of sound in water, thus we can calculate the depth of the sea.

According to the above information the correct option is A, echo.

Note – It’s a question of physics and general knowledge as well so you need to know that Sonar is simply making use of an echo. When an animal or machine makes a noise, it sends sound waves into the environment around it. Those waves bounce off nearby objects, and some of them reflect back to the object that made the noise. In much the same way that a bat uses sonar to locate and hunt its prey, the MIT group determined that ultrasonic frequencies can also be used to detect buried land mines, and even figure out who manufactured them. This array uses small devices that emit a narrow acoustic beam at ultrasonic frequencies. It is useful and at the same time disastrous if you are too close to it can kill human beings.