When a sound wave is reflected from a wall the phase difference between the reflected and incident pressure wave is:

Options

A. `0`
B. `pi`
C. `pi//2`
D. `pi//4`

Answer

A

Explanation

When a sound wave gets reflected from a rigid boundary , the particles at the boundary are unable to vibrate . Thus , a ref,ected wave is generated which interferes with the oncoming wave to produce zero displacement at the rigid boundary . At these points ( zero displacement) , the pressure variation is maximum . Thus , a reflected pressure wave has the same phase as the incident wave .