What is ultrasound? State the special properties of ultrasound that make it useful to us.
Ultrasound or ultrasonic wave is a wave in which the compressions and rarefactions in a material medium propagates with a frequency above 20 kHz.
Ultrasonic wave travels freely in solids and liquids but its intensity decreases rapidly in gases.
Ultrasonic waves have the following two important properties, because of their high frequencies:
1. They have high power.
2. They are able to travel along well-defined straight paths, even in the presence of obstacles.
The above two properties make the ultrasonic waves highly useful for industrial and medical purposes.