A single slit of width `0.20 mm` is illuminated with light of wavelength `500 nm`. The observing screen is placed `80 cm` from the slit. The width of the central bright fringe will be

Options

A. 1 mm
B. 5 mm
C. 10 mm
D. 4 mm

Answer

D

Explanation

Width of central bright fringe `= (2 lambda D)/(d)`
`= (2 xx 500 xx 10^(-9) xx 80 xx 10^(-2))/(0.2 xx 10^(-3))`
`4 xx 10^(-3)m`
Width of central brigt fringe = 4mm