Question

Two points are located at a distance of 10 m and 15 m from the source of oscillation. The period of oscillation is 0.05 sec and the velocity of the wave is 300 m/sec. What is the phase difference between the oscillations of two points?

• A. $\frac{\pi }{6}$
• B. $\frac{\pi }{3}$
• C. $\frac{2\pi }{3}$
• D. $\pi$

Answer 1

Answer: (C)

We know that,
Path difference $=\frac{2\pi }{\lambda }\times$ path difference
Path difference between two points,
$<br/>\Delta x=15-10=5m<br/>$
Time period, $T=0.5s$
$<br/>\Rightarrow \text{ frequency }v=\frac{1}{T}=\frac{1}{0.05}=20Hz<br/>$
Velocity $v=300m/s$
$\therefore$ Wavelenght $\lambda =\frac{v}{n}=\frac{300}{20}=15m$
Hence, phase difference
$<br/>\Delta \varphi =\frac{2\pi }{\lambda }\times x=\frac{2\pi }{15}\times 5=\frac{2\pi }{3}<br/>$