Physics - Wave Optics Question with Solution | TestHub

Wavelength of light, $\lambda =5000\text{ A˚}=5\times 10^{-7}\text{ m}$

Slit width, $a=10^{-6}\text{ m}$

For the first minimum in the diffraction pattern, the angular position $\theta$ is given by:

$a\sin \theta =\lambda$

$\sin \theta =\frac{\lambda }{a}=\frac{5\times 10^{-7}}{10^{-6}}=0.5$

$\theta =30^{\circ }$

The angular width of the central maximum is $2\theta$.

$2\theta =2\times 30^{\circ }=60^{\circ }$