CAPE Physics Unit 1 · 2015 · Paper 1 · Question Q22

In a double slit experiment using a monochromatic light source of wavelength 400\text{ nm}, the distance between the bright fringes was found to be 8.0\text{ mm}. If the screen is 5\text{ m} from the double slit, what is the slit separation?

1. (A)1.0 \times 10^{-5}\text{ m}
2. (B)2.5 \times 10^{-4}\text{ m}
3. (C)1.0 \times 10^{-3}\text{ m}
4. (D)2.5 \times 10^{-2}\text{ m}