Question

The speed of wave in a medium is $760m/s$. If $3600$ waves are passing through a point in the medium in $2$ minutes, then its wavelength is

• A. $13.8m$
• B. $25.3m$
• C. $41.5m$
• D. $57.2m$

Answer 1

Answer: (B)

$25.3m$

Given,

$v=760m/s$
$n=3600$
$t=2\times 60sec=120sec$

$f=\frac{n}{time}=\frac{3600}{2\times 60}=30Hz$

The relation between frequency $f$, wavelength $\lambda$ and speed $v$ is given by

$v=\lambda f$

$\lambda =\frac{v}{f}$

$\lambda =\frac{760}{30}=25.3m$

The correct option is B.