A parallel beam of monochromatic light of wavelength `5000Å` is incident normally on a single narrow slit of width `0.001mm`. The light is focused by a convex lens on a screen placed on the focal plane. The first minimum will be formed for the angle of diffraction equal to

Options

A. `0^(@)`
B. `15^(@)`
C. `30^(@)`
D. `60^(@)`

Answer

C

Explanation

In single narrow slit, for first minima,
`d sin theta=lambda rArr sin theta=lambda/d`
`theta=sin^(-1)((5000xx10^(-10))/(0.001xx10^(-3)))=30^(@)`