In a biprism expeirment the slit is illuminated with light of waveleght 6000Å. The distance between the slit and eye piece is `0.9`m. The virtual images of the slit s are formed 3 mm apart. The source is then replaced by another sources of light of wavelength 5400Å. The slit and biprims are not disturbed. The distance betwene the slit and eyepiece to get the same band width s before is 2 m

Options

A. 2 mm
B. 1 m
C. `0.5 m`
D. 1cm

Answer

B

Explanation

`beta_(1)=beta_(2)`
`:.(D_(1))/(d)lamda_(1)=(D_(2))/(d)lamda_(2)`
`:.D_(2)=(0.9xx6)/(5.4)=1m`