Section-C: Comprehension Type
The longitudinal waves in a liquid is described either by displacement of the fluid molecules or by pressure variations created in the fluid during the propagation of waves. A displacement node is a point where the displacement of the particle is zero and a displacement antinode is one where the displacement is maximum. The air column in a pipe closed at one end is made to vibrate in its second overtone by a tuning fork of frequency 440 Hz. The speed of sound in air is 330 ms-1. End corrections may be neglected. Let P0 denote the mean pressure at any point in the pipe, and ΔP0 the maximum amplitude of pressure variation.
The amplitude of pressure variation at the middle of the air column is