Angular width of a central max. is 30° when the slit is illuminated by light of wavelength 6000 Å. Then width of the slit will be approx.
Answer & explanation
Correct answer: option 2
Angular width = 2θ = 30°
$∴\sin 30° =\frac{λ}{a}$
$∴a=\frac{λ}{\sin 30°} =\frac{6000×10^{-10}}{1/2}=12000×10^{-10} m$
$=12 × 10^{–7} m$