In a double-slit setup

PHYSICS · Subjective · A Level · Physics · Waves · Waves

Problem

In a double-slit setup, the fourth-order bright fringe is observed

25\,\text{mm}

above the central maximum on a screen

1.2\,\text{m}

away. The slit separation is

0.15\,\text{mm}

. Using these data, compute the wavelength of the light.