Physics (AS & A Level) · Oct / Nov 2018 · Paper 13 · Question 29

A parallel beam of white light is incident normally on a diffraction grating. The second-order and third-order spectra partially overlap. Which wavelength in the third-order spectrum appears at the same angle as the wavelength of 600 nm in the second-order spectrum?

1. A300 nm
2. B400 nm
3. C600 nm
4. D900 nm

As printed in the paper