Wave Optics Question 5
Question 5 - 2024 (27 Jan Shift 2)
A parallel beam of monochromatic light of wavelength $5000 \bullet \AA$ is incident normally on a single narrow slit of width $0.001 \mathrm{~mm}$. The light is focused by convex lens on screen, placed on its focal plane. The first minima will be formed for the angle of diffraction of (degree).
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Answer: (30)
Solution:
For first minima
$a \sin \theta=\lambda$
$\Rightarrow \sin \theta=\frac{\lambda}{\mathrm{a}}=\frac{5000 \times 10^{-10}}{1 \times 10^{-6}}=\frac{1}{2}$
$\Rightarrow \theta=30^{\circ}$
