QUESTIONS

Fraunhofer diffraction from a single-slit of width $1.0 \mathrm{\mu m}$ is observed with light of wavelength $500 \mathrm{nm}$. Calculate the half angular width of the central maximum.

Fraunhofer diffraction from a single-slit of width $1.24\times {10}^{-6} \mathrm{m}$ is observed with light of wavelength $6200 \mathrm{\AA }$. Calculate the angular width of the central maximum.

A parallel beam of light of wavelength $600 \mathrm{nm}$ falls normally on a narrow slit of width $0.3 \mathrm{mm}$. Calculate the angular separation between the first minimum and the central maximum.

A parallel beam of light of wavelength $600 \mathrm{nm}$ falls normally on a narrow slit of width $0.3 \mathrm{mm}$. Calculate the angular separation between the first subsidiary maxima on the two sides of the central maximum.

A parallel beam of light of wavelength $6\times {10}^{-5} \mathrm{cm}$ falls normally on a straight slit of width $0.2 \mathrm{mm}$. Find the total angular width of the central diffraction maximum and also its linear width as observed on a screen placed $2$ metre away.

A Fraunhofer diffraction pattern due to a single-slit of width $0.2 \mathrm{mm}$ is being obtained on a screen placed at a distance of $2$ metre from the slit. The first minima lie at $5 \mathrm{mm}$ on either side of the central maximum on the screen. Find the wavelength of light.

A narrow slit of width $0.3 \mathrm{mm}$ is illuminated normally by a parallel beam of light of wavelength $6\times {10}^{-7} \mathrm{m}$. The Fraunhofer diffraction pattern is obtained on a screen placed in the focal plane of a convex lens of focal length $25 \mathrm{cm}$. The lens is placed quite close to the slit. Find the width of central maximum on the screen.

A parallel light beam of wavelength $6000 \mathrm{\AA }$ passes through a slit $0.2 \mathrm{mm}$ wide and forms a diffraction pattern on a screen $1.0 \mathrm{m}$ away from the slit. Find the width of the central maximum on the screen. What would be the width of this maximum, if the apparatus be immersed in water of refractive index $\frac{4}{3}$?