in a two-slit experiment with monochromatic light, fringes are obtained on a screen placed at some distance from the slits. If the screen is moved by `5xx10^(-2)` m towards the slits, the change in fringe width is `3xx10^(-5)`. If the distance between the slits is `10^(-3)`m, calculate the wavelength of the light used.

Options

A. 4000 Å
B. 4500 Å
C. 5000 Å
D. 6000 Å

Answer

D

Explanation

`beta= (lambdaD)/(d) implies Deltabeta= (lambdaDeltaD)/(d)= lambda= (10^(-3) xx 0.03 xx 10^(-3))/(5 xx 10^(-2))= 6000Å`