CAPE Physics Unit 1 · 2005 · Paper 2 · Question 7(b)(i)

Two loudspeakers connected in parallel to a signal generator are used to demonstrate the interference of sound waves, analogous to light. Figure VI illustrates the setup. As a microphone moves along line YX, it detects a maximum of sound intensity at O and then another maximum at X. Velocity of sound in air = 330 ms⁻¹.

Find the distances PX and QX from the speakers to the first maximum at X and hence find the wavelength of the sound waves.

This question uses a figure or table from the paper — you'll see it when you practise.