Wave Optics Question 1
Question 1 - 2024 (01 Feb Shift 1)
A monochromatic light of wavelength $6000 \AA$ is incident on the single slit of width $0.01 \mathrm{~mm}$. If the diffraction pattern is formed at the focus of the convex lens of focal length $20 \mathrm{~cm}$, the linear width of the central maximum is :
(1) $60 \mathrm{~mm}$
(2) $24 \mathrm{~mm}$
(3) $120 \mathrm{~mm}$
(4) $12 \mathrm{~mm}$
Show Answer
Answer: (2)
Solution:
Linear width
$\begin{aligned} \mathrm{W} & =\frac{2 \lambda \mathrm{d}}{\mathrm{a}}=\frac{2 \times 6 \times 10^{-7} \times 0.2}{1 \times 10^{-5}} \ & =2.4 \times 10^{-2}=24 \mathrm{~mm}\end{aligned}$
