Question

What will be the angle of diffraction for the first order maximum due to Fraunhofer diffraction by a single slit of width $0.50mm$, using light of wavelength $500nm$?

• A. $1\times {10}^{-3}rad$
• B. $3\times {10}^{-3}rad$
• C. $1.5\times {10}^{-4}rad$
• D. $1.5\times {10}^{-3}rad$

Answer 1

The correct option is A $1\times {10}^{-3}rad$

Using $d\sin \theta =n\lambda$, for $n=1$
$\sin \theta =\frac{\lambda }{d}=\frac{500\times {10}^{-9}}{0.5\times {10}^{-3}}={10}^{-3}rad$.