Question

Consider single slit experiment of diffraction of light. If the light of wavelength $5000 \, \mathring{A}$ fall on a slit of width $1 \, \mu m$ then the angular width of central maximum is

• A. $30^\circ $
• B. $15^\circ $
• C. $60^\circ $
• D. None of these

Answer 1

Answer: (C)

$dsin \theta =\lambda \, $
$sin \theta =\frac{\lambda }{d} \, $
For first minima
$=\frac{5 \, \times \, 10^{- 7}}{10^{- 6}}$
$sin \theta =\frac{5}{10}$
$\theta =30^\circ $ Angular width of first minima

$2\theta =60^\circ $