Question

What is the principle for measurement of velocity of ultrasonic waves?

Answer 1

the velocity of sound wave having a frequency of 108 600 cycles per second has been measured in water vapour by a method of similar to that used by pierce for other gases

Answer 2

The principle used for the measurement of the velocity of ultrasonic waves is acoustical grating.

• Acoustical grating: When an ultrasonic wave is passed through a transparent liquid, the liquid will act as a diffraction grating or there is diffraction of the wave due to variation in the pressure. This condition is called acoustical grating.
• Therefore, whenever a monochromatic light is passed through this acoustical grating condition, the light gets diffracted by which we can find the velocity of the ultrasonic waves.