Question

In a medium in which a transverse progressive wave is travelling, the phase difference between two points with a separation of 1.25 cm is $\left(\frac{\pi }{4}\right)$. If the frequency of wave is 1000 Hz its velocity will be

• A. 104 m/s
• B. 125 m/s
• C. 100 m/s
• D. 10 m/s

Answer 1

The correct option is C

100 m/s

$\Delta \varphi =\frac{2\pi }{\lambda }\Delta x\frac{\pi }{4}=\frac{2\pi }{\lambda }\times \frac{1.25}{100}$

On solving we get

$\lambda =\frac{1}{10}mv=n\lambda =1000\times \frac{1}{10}=100m/s$