Physics (AS & A Level) · May / June 2019 · Paper 11 · Question 30

The interference patterns from a diffraction grating and a double slit are compared. Using the diffraction grating, yellow light of the first order is seen at 30° to the normal to the grating. The same light produces interference fringes on a screen 1.0 m from the double slit. The slit separation is 500 times greater than the line spacing of the grating. What is the fringe separation on the screen?

1. A2.5 × 10⁻⁷ m
2. B1.0 × 10⁻⁵ m
3. C1.0 × 10⁻³ m
4. D1.0 × 10⁻¹ m

As printed in the paper