Question

The diagram below shows three different modes of vibration P, Q and R of the same string of a givens length.

(a) Which vibration will produce a louder sound and why?

(b) Which vibration will produce sound of maximum shrillness (of pitch) and why ?

(c) What is the ratio of wavelength of vibrations P and R ?

Answer 1

(a) Vibration R is the loudest as its amplitude is the maximum.

(b) Vibration P will have maximum shrillness as its frequency is maximum.

(c) In P, three waves are formed, while in R, a single wave is formed.

Let $l$ be the length between the ends.

So, 3λ_P = 1λR

Hence, λ_P : λ_R = 1:3