Question

The frequency and velocity of sound wave are 600 Hz and 360 m/s respectively. Phase difference between two particles of medium are $ 60{}^\circ , $ the minimum distance between these two particles will be

• A. 10 cm
• B. 15 cm
• C. 20 cm
• D. 50 cm

Answer 1

Answer: (B)

Velocity of wave (v)= 360 m/s
Frequency, $ n=600\text{ }Hz
$ Phase difference, $ \phi =60{}^\circ $
If the minimum distance between two points is
$ \Delta x $ then $ \Delta x=\frac{\lambda }{2\pi }\times \Delta \phi $
Or $ \Delta x=\frac{V}{2\pi n}\times \Delta \phi $
Or $ \Delta x=\frac{360}{2\pi \times 600}\times 60 $
$ \Delta x=\frac{360}{2\pi \times 600}\times \frac{\pi }{3} $
$ \Delta x=\frac{1}{10}m $
$ \Delta x=10\,cm $