Question

Light of wavelength 5.0 x 10^–7 meter in air is incident normally (perpendicularly) on a double slit. The distance between the slits is 4.0 x 10^–4 meter, and the width of each slit is negligible. Bright and dark fringes are observed on a screen 2.0 meters away from the slits.

a. Calculate the distance between two adjacent bright fringes on the screen.

Answer 1

(a) Simple application of the formula, m λ = d x / L … (1)(5 x 10^–7) = (4 x 10^–4)(x) / (2) … x = 2.5 x 10^–3 m