Physics (AS & A Level) · May / June 2016 · Paper 13 · Question 27

A diffraction grating with N lines per metre is used to deflect light of various wavelengths λ. The graph shows a relation between the deflection angle θ and λ for different wavelengths in the nth order interference pattern. [graph of sin θ against λ] What is the gradient of the graph?

1. ANn
2. BN/n
3. Cn/N
4. D1/(Nn)

As printed in the paper