Question

Two sound waves of equal amplitude interfere so that the compression of one wave falls on the rarefaction of the other.Which statement is true?
A.No sound is heard.
B.The loudness of the sound increases.
C.There is no change in the sound.
D.The pitch of the sound increased.

Answer 1

Two sound waves of equal amplitude interfere so that the compression of one wave falls on the rarefaction of the other. The statement which is true is that A. no sound is heard.
These waves interfere, which means that their equal amplitudes match and thus cancel each other out, which is why there is no sound.

Answer 2

Answer;

A.No sound is heard.

Explanation;

• Interference of a wave is the property a wave that occurs when two waves travelling in the same medium meet at a point or superpose at a point in the medium.

• Interference may be constructive or destructive. Constructive occurs when two identical waves travelling in the same medium in phase meet at a point. The resulting wave has twice the amplitude of the individual waves.

• Destructive interference occurs when two waves travelling in the same medium meet and out of phase. The resulting amplitude will be zero if the initial waves are identical, or the difference between the amplitude of the original waves if they are not identical.
• In this case, the two sound waves are out of phase since the compression of one wave falls on the rarefaction of the other, and thus these waves cancel out and the resulting amplitude is zero and hence no sound will be heard.