Question

Why is a loud sound heard at resonance ?

Answer 1

At resonance, a compression of one wave falls on a compression of another wave and a rarefaction on a rarefaction. On account of this, the amplitude of the vibrating particle increases. Since the intensity of sound is directly proportional to the square of the amplitude of the vibrating particles ( I∝ $A^2$) maximum sound is heard (loud sound)at resonance closed pipe for same fundamental frequency.