A Young's double slit experiment is conducted with slit separation 10mm, where the screen is 2m away from the slits. If wavelength of light used is `6000 Å` , answer the following
Fringe width in mm is

Options

A. 1.15 mm
B. 0.30 mm
C. 0.24 mm
D. 0.12 mm

Answer

A

Explanation

Given, `lambda=6000 "Å"=6000xx10^(-10)m`
`D=25cm=25xx10^(-2)m`
`d=1mm =1xx10^(-3)m`
`therefore` The fringe width on the screen
`beta=(Dlambda)/(d)=(6000xx10^(-10)xx25xx10^(-2))/(1xx10^(-3))=1.5xx10^(-4)`
`=0.15 xx 10^(-3)m =0.15 mm `