Displacement distance graph of two sound waves A and B, travelling in a medium, are as shown in the diagram below.

(i) From figure, amplitude of wave A = 20 cm and

amplitude of wave B = 10 cm.

$\frac{\text{Amplitude of wave A}}{\text{Amplitude of wave B}} = \frac{20}{10} = 2 : 1$

(ii) Wavelength of A = x and wavelength of B = 2x

$\frac{\text{Wavelength of wave A}}{\text{Wavelength of wave B}} = \frac{x}{2x} = 1 : 2$