Question

1. Name the waves used for echo depth sounding. 

2. Give one reason for their use for the above purpose. 

3. Why are the waves mentioned by you not audible to us?

Answer 1

(i) The waves used for echo depth sounding are ultrasound waves. 

(ii) Ultrasound waves are used for echo depth ranging because they can travel undeviated through a long distance. 

(iii) Ultrasonic waves have frequency larger than 20000Hz. Hence, these waves are not audible to us as the audible range for the human ear is 20Hz to 20000Hz.