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Question
A monochromatic light of wavelength 500 nm is incident normally on a single slit of width 0.2 mm to produce a diffraction pattern. Find the angular width of the central maximum obtained on the screen.
Estimate the number of fringes obtained in Young's double slit experiment with fringe width 0.5 mm, which can be accommodated within the region of total angular spread of the central maximum due to single slit.
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Solution
The angular width of the central maximum obtained on the screen.
`=(2λ)/d`
`=(2×500×10^-9)/(0.2×10^-3)`
`=5×10^-3 m`
The number of fringes obtained in Young's double slit experiment
`"Angular width"/"Fringe width"=(5×10^-3)/(0.5×10^-3)=10`
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