A laser with wavelength illuminates a single slit

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

Problem

A laser with wavelength

650\,\text{nm}

illuminates a single slit. The third diffraction minimum is observed at an angle of

2.5^{\circ}

from the central axis. What is the width of the slit? (a)

0.030\,\text{mm}

(b)

0.045\,\text{mm}

(c)

0.022\,\text{mm}

(d)

0.052\,\text{mm}