Can we hear (a) infrasonic waves (b) ulfrasonic waves ?
No. We can hear sounds only in the range of 20 Hz-20kHz. Ultrasonic sound waves have frequencies more than 20 kHz while infrasonic waves have frequency less than 20 Hz.
In SONAR we use :
(a) ultrasonic waves
(b) infrasonic waves
(c) radio waves
(d) audible sound waves
To detect the obstacles in their path, bats produce :
(a) infrasonic waves (b) ultrasonic waves
(c) electromagnetic waves (d) radio waves.