SONAR is a device that is used to measure the distance of underwater objects by a ship. Which of the following types of waves does it use for this purpose?

Which one of the following units is used for measurement of noise pollution?

What is the name of the device used to measure sound intensity?

Which one of the following does not apply to sound waves in fluids?

Which one of the following statements is true for sound waves propagating in air?

Which among the following is true for propagation of sound waves ?