Physics (AS & A Level) · May / June 2019 · Paper 13 · Question 26

An elastic string is attached to an oscillator at one end and clamped at the other end so that the string is horizontal and in tension. The oscillator is made to oscillate vertically. The frequency of oscillation is gradually increased from zero until a stationary wave is set up in the string. The frequency is then increased further to frequency f, when a second stationary wave is set up in the string. The frequency is then increased further. At which frequency does a third stationary wave occur?

1. A1.2f
2. B1.5f
3. C2.0f
4. D3.0f

As printed in the paper