Physics (AS & A Level) · May / June 2019 · Paper 13 · Question 29

Apparatus is arranged to show double-slit interference using monochromatic light. The slit separation is 0.10 mm. The distance from the double slit to the screen where the interference pattern is observed is 2.4 m and the fringe width is 12 mm. The distance to the screen is now changed to 1.8 m and the slit separation is doubled. What is the new fringe width?

1. A1.5 mm
2. B4.5 mm
3. C6.0 mm
4. D9.0 mm

As printed in the paper