Q. In Young’s double slit experiment, slit separation is 0.6 mm and the separation between slit and screen is 1.2 m. The angular width is (the wavelength of light used is $4800\ \mathring{\mathrm{A}}$
A) 30 rad
B) $8 \times 10^{- 4}\ $rad
C) 12 rad
D) 70.5 rad
Explanation
(b) Angular width $\theta = \frac{\beta}{D}$
$= \frac{\lambda}{d} = \frac{4800 \times 10^{- 10}}{0.6 \times 10^{- 3}} = 8 \times 10^{- 4}$ rad
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.