Question

Determine the half angular width of the central maximum, if a wavelength of 1000 nm is observed when diffraction occurs from a single slit of 2 μm width.

(a) 100^o

(b) 30^o

(c) 90^o

(d) 150^o

I got this question in an internship interview.

My doubt is from Wave Optics in division Wave Optics of Physics – Class 12

Answer 1

Right option is (b) 30^o

Explanation: Half angular width of the central maximum is given by:

Sin θ = \(\frac {\lambda }{d}\)

Sin θ =  \(\frac {1000 \times 10^{-9}}{2 \times 10^{-6}}\)

Sin θ = 0.5.

Θ = 30^o