Question

A wave of wavelength 4 mm is produced in air and it travels at a speed of 300 m/s. Will it be audible?

• A. $20,000Hz$
• B. $70000Hz$
• C. $92000Hz$
• D. $90000HZ$

Answer 1

The correct option is A $20,000Hz$

We have , $v=f\lambda$ ,

or $f=v/\lambda$ ,

given $\lambda =4mm=0.004m,v=300m/s$ ,

therefore , frequency

$f=300/0.004=75000Hz$ ,

this frequency is not audible because audible frequency range is from 20Hz to 20,000Hz , and 75000Hz is above 20,000Hz.