Q. Sonar is a device that uses ultrasonic waves to measure the distance, direction and speed of?

[A] Space objects

[B] Under water objects

[C] Missile detection

[D] Cyclone

Answer: B
Notes:

Explanation: The acronym SONAR stands for SOund Navigation And Ranging. Sonar is a device that uses ultrasonic waves to measure the distance, direction and speed of underwater objects.

Source: Science NCERT