In a biprism experiment, interfernce bands are obtined in the focal of the eyepiece which is at a distance of `1.2` m from the slit. The distance between the two virtual images of the slits is 1 mm. If the slit is illuminated by light of wavelenght 4800Å. The change in band width when the eyepiece is moved towards other the slit by 50 cm without distrubing the other arrangement is

Options

A. `1.24 mm`
B. `2.24 mm`
C. `0.24 mm`
D. `1.1 mm`

Answer

C

Explanation

` beta_(1)=(D_(1))/(d)lamda" "beta_(2)=(D_(2))/(d)lamda`
`beta_(1)-beta_(2)=((D_(1)-D_(2))lamda)/(d)=(0.5xx4.8xx10^(-7))/(10^(-3))`
=0.24mm