Jee Main 2024 01 02 2024 Shift 1 - Question15
Question 15
In single slit diffraction with slit width $0.1 mm$, light of wavelength $6000 \mathring{A}$ is used. A convex lens of focal length $20 cm$ is used to focus the diffracted ray. Find width of central maxima.
(1) $24 mm$
(2) $2.4 mm$
(3) $12 mm$
(4) $1.2 mm$
Show Answer
Answer: (2)
Solution:
Angular width $=\frac{2 \lambda}{a}$
$$ \begin{aligned} \text { Linear width } & =\frac{2 \lambda}{a} f \\ & =\frac{2 \times 6000 \times 10^{-10} \times 20 \times 10^{-2}}{0.1 \times 10^{-3}} \\ & =2 \times 6 \times 2 \times 10^{-4} \\ & =24 \times 10^{-4} \\ & =2.4 mm \end{aligned} $$
BETA
