What is the effect on the interence pattern in Young's double slit experiment if
(i) screen is moved away from the slits
(ii) separation between the slits is increased

Explanation

The width of interference fringes in Young's double slit experiment `y=(D)/(2d) lambda`
Here D = distance of the screen from the slits
2d = separation between the two slits
`lambda` = wavelength of light.
(i) If the screen is moved away D would increase and so this fringe width would also increase.
(ii) If the separation 2d is increased this fringe width would decrease.