A double-slit apparatus has slit separation and is illuminated by light of wavelength

PHYSICS · Single correct · A Level · Physics · Waves · Waves

Problem

A double-slit apparatus has slit separation

d = 0.40\,\text{mm}

and is illuminated by light of wavelength

\lambda = 550\,\text{nm}

. A viewing screen is placed

L = 2.0\,\text{m}

from the slits. Calculate the distance of the second-order (

m = 2

) bright fringe from the central maximum. (a)

6.9\,\text{mm}

(b)

0.55\,\text{mm}

(c)

5.5\,\text{mm}

(d)

2.8\,\text{mm}