Question

Which one of the following statement is not 930E correct?

(a) Sound waves in gases are longitudinal in nature.

(b) Sound waves having frequency below 20 Hz are known as ultrasonic waves.

(c) Sound waves having higher amplitudes are louder. 

(d) Sound waves with high audible frequencies are sharp.

Answer 1

(b) Sound waves having frequency below 20 Hz are known as ultrasonic waves.

Sound waves of frequency less than 20 Hz is known as infrasonic sound or infrasound.

Sound waves of frequency greater than 20 kHz is known as ultrasonic sound or ultrasound.

Sound waves are longitudinal waves. Higher amplitude sound waves are louder, whereas high frequency sound waves are sharp.