Give the formula for angular separation of bright and dark fringes.

Explanation

(a) For bright fringes , semi angular width is given by `theta-sin^(-1) ((n lambda)/(d))` where, `n=1,2,3,…....`
(b) For dark fringes, semi angular width is given by `theta=sin^(-1)(((2n+1)lambda D)/(2d))` where, `n=0,1,2,3,…........`