A narrow slit of width 2 mm is illuminated by monochromatic light fo wavelength 500nm. The distance between the first minima on either side on a screen at a distance of 1 m is

Options

A. `5` mm
B. `0.5` mm
C. `1` mm
D. `10` mm

Answer

B

Explanation

Here, `a=2mm=2xx10^(-3)m,D=1m`
`lambda=500nm=500xx10^(-9)m=5xx10^(-7)m`
The distance between the first minima on either side on a screen is
`=(2lamdaD)/(a)=(2xx5xx10^(-7)xx1)/(2xx10^(-3))`
`=5xx10^(-4)m=0.5xx10^(-3)m=0.5mm`