wave_mechanics basics_of_mechanical_waves Question 76

Question: A wave of frequency 500 Hz has velocity 360 m/sec. The distance between two nearest points 60° out of phase, is

[NCERT 1979; MP PET 1989; JIPMER 1997; RPMT 2002, 03; CPMT 1979, 90, 2003; BCECE 2005]

Options:

A) 0.6 cm

B) 12 cm

C) 60 cm

D) 120 cm

Show Answer

Answer:

Correct Answer: B

Solution:

The distance between two points i.e.

path difference between them $ \Delta =\frac{\lambda }{2\pi }\times \varphi =\frac{\lambda }{2\pi }\times \frac{\pi }{3}=\frac{\lambda }{6}=\frac{v}{6n} $

$ (\because v=n\lambda ) $

Therefore $ \Delta =\frac{360}{6\times 500}=0.12m=12cm $