Physics (AS & A Level) · May / June 2022 · Paper 13 · Question 30

A beam of light from a laser is incident normally on a double slit. Interference fringes are seen on a screen placed parallel to the double slit. The separation of the two slits is a. The distance between the slits and the screen is D. The distance between the centres of two adjacent bright fringes is x. D and a are both halved. What is the distance between the centres of two adjacent bright fringes after these changes?

1. Ax/2
2. Bx
3. C2x
4. D4x

As printed in the paper