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, $n=600Hz<br>$ Phase difference, $\varphi =60{}^{\circ }$
If the minimum distance between two points is
$\Delta x$ then $\Delta x=\frac{\lambda }{2\pi }\times \Delta \varphi$
Or $\Delta x=\frac{V}{2\pi n}\times \Delta \varphi$
Or $\Delta x=\frac{360}{2\pi \times 600}\times 60$
$\Delta x=\frac{360}{2\pi \times 600}\times \frac{\pi }{3}$
$\Delta x=\frac{1}{10}m$
$\Delta x=10cm$