Question

A progressive wave moves with a velocity of $36m/s$, in a medium with a frequency of $200Hz$. The phase difference between two particles, separated by a distance of $1cm$ is :

• A. ${40}^o$
• B. $20rad$
• C. $\frac{\pi }{9}rad$
• D. $\frac{{\pi }^2}{9}$

Answer 1

The correct option is C $\frac{\pi }{9}rad$

We have the equation,

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

$\lambda =\frac{36}{200}$

Also,

$\Delta \varphi =\frac{2\pi }{\lambda }\Delta x$

$=\frac{2\pi }{36}\times 200\times 0.01$

$=\frac{2\pi \times 2}{36}=\frac{\pi }{9}$