A screen is placed $50cm$ from a single slit, which is illuminated with $6000\mathring{\mathrm{A}}$ light. If distance between the first and third minima in the diffraction pattern is $3mm$, the width of the slit is

Question

Dr. Abubacker · Accepted Answer

(b) Position of $n^{th}$ minima $y_{n} = \frac{n 	imes D}{d}$
$\Rightarrow y_{3} - y_{1} = \frac{D}{d}(3\lambda - \lambda) = \frac{2\lambda D}{d}$
$\Rightarrow 3 	imes 10^{- 3} = \frac{2 	imes 6000 	imes 10^{- 10} 	imes 0.5}{d}$
$\Rightarrow d = 0.2 	imes 10^{- 3}m = 0.2mm$

Q. A screen is placed $50cm$ from a single slit, which is illuminated with $6000\mathring{\mathrm{A}}$ light. If distance between the first and third minima in the diffraction pattern is $3mm$, the width of the slit is

Explanation

Reviewed by Dr. Abubacker

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