In YDSE with monochromatic light, fringes are obtained on the screen placed at some distance from the slits. If screen is moved by `5 xx 10^(–2)m` towards the slits, fringe width changes by `3 xx 10^(-5) m`. If separation between the slits is 10–3 m, if wavelength of light used is 1000 y Å, then y is : (Assume distance between the two slits is very small than the distance betwen the slits and screen)

Explanation

`(lambdaD_(1))/d-(lambdaD_(2))/d=3xx10^(-5)`
`lambdaxx(5xx10^(-2))/(10^(-3))=3xx10^(-5) rArr lambda=0.6 xx10^(-6) =6000Å`