Wave Mechanics Question 54

Question: The phase difference between two points separated by 1m in a wave of frequency 120 Hz is $ 90^{o} $ . The wave velocity is

[KCET 1999]

Options:

A) 180 m/s

B) 240 m/s

C) 480 m/s

D) 720 m/s

Show Answer

Answer:

Correct Answer: C

Solution:

Path difference $ \Delta =\frac{\lambda }{2\pi }\times \varphi $

Therefore $ 1=\frac{\lambda }{2\pi }\times \frac{\pi }{2} $

Therefore l = 4m Hence $ v=n\lambda $ = $ 120\times 4=480 $

$ m/s $