Physics (AS & A Level) · May / June 2022 · Paper 11 · Question 30

Light of wavelength 5.4 × 10⁻⁷ m is incident normally on a diffraction grating. The separation between adjacent lines in the grating is 2.0 × 10⁻⁶ m. The light that emerges from the grating falls on a semicircular screen, as shown in the view from above. The grating is at the centre of the semicircle, and the lines of the grating are vertical. How many bright dots are formed on the screen?

1. A3
2. B4
3. C6
4. D7

As printed in the paper