Question

In a string the speed of wave is $10m/s$ and its frequency is $100$ Hz. The value of the phase difference at a distance $2.5$cm will be :

• A. $\pi /2$
• B. $\pi /8$
• C. $3\pi /2$
• D. $4\pi$

Answer 1

The correct option is A $\pi /2$

Given,

$f=100Hz$

$x=2.5cm$

$v=10m/s$ path difference

wavelength, $\lambda =\frac{v}{f}=\frac{10}{100}=0.1m$

The phase difference, $\varphi =\frac{2\pi }{\lambda }\times x$

$\varphi =\frac{2\pi }{0.1}\times 2.5\times {10}^{-2}$

$\varphi =\frac{\pi }{2}$

The correct option is A.