Question

If sound waves are reflected from surface of denser medium, there is phase change of ............

• A. 0 rad
• B. $\frac{\pi }{4}$ rad
• C. $\frac{\pi }{2}$
• D. $\pi$ rad

Answer 1

The correct option is D $\pi$ rad

There is a phase change of ${180}^o$, i.e. the phase of the wave changes by $\pi$ radians.When wave get reflected from m open end there is no change in the phase , but when it get reflected from the closed or denser end the phase get changed . Phase is zero in open surface and $\pi$ radian when reflected from denser medium