Two speakers are placed as shown in Fig.7.98.
Mark out the correct statement(s)

Options

A. If a person is moving along `AB` , he will hear the sound as loud , faint , loud and so on
B. If a person moves along `CD`, he will hear loud , faint , loud and so on
C. If a person moves along `AB` , he will hear uniform intense sound
D. If a person moves along `CD` , he will hear uniform intense sound

Answer

B, C

Explanation

At any point on line `AB` , the phase difference between two waves is zero and hence waves will interfere constructively .
Along `CD` , the phase difference changes and waves interfere constructively and destructively and , hence sound will be loud , faint and so on .