Question

Which of the following correctly represents the increasing order of frequency for infrasound,ultrasound and audible sound?

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

Answer 1

The correct option is A Infrasound < Audible < Ultrasound


Sounds can be classified broadly into three categories based on its frequency:
Audible sound: The range of frequency audible to humans - 20 Hz to 20kHz.
Infrasound: The range of frequency < 20 Hz.
Ultrasound: The range of frequency > 20 kHz.
Therefore, audible sound lies in between infrasound and ultrasound, i.e. Infrasound < Audible sound < Ultrasound.