Physics (AS & A Level) · May / June 2021 · Paper 11 · Question 23

A stationary wave is formed from two identical sound waves. A microphone is placed at a position of maximum loudness. It is then moved along the stationary wave from this first position of maximum loudness to the fourth position of maximum loudness. The microphone moves a distance of 12 cm. The speed of sound is 330 m s–1. What is the frequency of the sound waves?

1. A4100 Hz
2. B5500 Hz
3. C8300 Hz
4. D11 000 Hz

As printed in the paper