Physics (AS & A Level) · May / June 2018 · Paper 13 · Question 21

The four graphs represent a progressive wave on a stretched string. Graphs A and B show how the displacement d varies with distance x along the string at one instant. Graphs C and D show how the displacement d varies with time t at a particular value of x. The labels on the graphs are intended to show the wavelength λ, the period T and the amplitude a of the wave, but only one graph is correctly labelled. Which graph is correctly labelled?

1. AGraph A
2. BGraph B
3. CGraph C
4. DGraph D

As printed in the paper