Physics (AS & A Level) · Oct / Nov 2024 · Paper 12 · Question 30

The diagram shows visible light incident normally on a diffraction grating. A pattern of intensity maxima forms on the screen. A line connecting the centre of the fourth order intensity maximum with the centre of the diffraction grating forms an angle of 53° with the centre line. The grating has a line spacing of 2.7 × 10⁻⁶ m. What is the wavelength of the incident light?

1. A4.1 × 10⁻⁷ m
2. B5.4 × 10⁻⁷ m
3. C1.6 × 10⁻⁶ m
4. D2.2 × 10⁻⁶ m

As printed in the paper