The ratio of amplitude of two waves is 3 : 4. What is the ratio of their :

Given, a₁ : a₂ = 3 : 4

(i) Since, loudness ∝ (amplitude)²

Therefore,

$\frac{L_1}{L_2} = \Big(\frac{a_1}{a_2}\Big)^2 = \Big(\frac{3}{4}\Big)^2 = \frac{9}{16}$

(ii) The frequency of sound does not depend on it's amplitude, so the ratio of frequency f₁ : f₂ = 1 : 1