In a Fraunhofer diffraction at a single slit of width $d$ and incident light of wavelength $5500 \mathrm{~A}$, the firs minimum is observed at an angle $30^{\circ}$. The first secondary maxima are observed at an angle $ heta=$

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In a Fraunhofer diffraction at a single slit of width $d$ and incident light of wavelength $5500 \mathrm{~A}$, the firs minimum is observed at an angle $30^{\circ}$. The first secondary maxima are observed at an angle $	heta=$

Aicharya · Accepted Answer

Slit width $=d$ $\lambda=5500 Å=5.5 	imes 10^{-7} \mathrm{~m}, 	heta_1=30^{\circ}$ For first secondary minima, $d \sin 	heta_1=\lambda$ $d=\frac{\lambda}{\sin 	heta_1}=\frac{5.5 	imes 10^{-7}}{\sin 30^{\circ}}=11 	imes 10^{-7}$ For first secondary maxima, $d \sin 	heta_1=\frac{3 \lambda}{2}$ $\begin{aligned} & \Rightarrow \sin 	heta_1=\frac{3 \lambda}{2 d}=\frac{5.5 	imes 10^{-7}}{2 	imes 11 	imes 10^{-7}}=\frac{3}{4} \ & 	heta_1=\sin ^{-1}\left(\frac{3}{4}ight)\end{aligned}$

In a Fraunhofer diffraction at a single slit of width $d$ and incident light of wavelength $5500…

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