Question

Which of the following correctly represents the increasing order of frequency?

• A. Infrasound < Audible Range < Ultrasound
• B. Ultrasound < Audible Range < Infrasound
• C. Audible Range < Ultrasound < Infrasound
• D. Ultrasound = Audible Range = Infrasound

Answer 1

The correct option is A

Infrasound < Audible Range < Ultrasound

The sound of frequencies in the range of $20Hz$ to $20kHz$ is called the sonic or audible sound. The sound of frequency less than $20Hz$ is known as infrasound (or infrasonic). While the frequency greater than $20kHz$ is known as ultrasound (or ultrasonic).