question_answer

What is the effect on the interference fringes in Young's double slit experiment if (i) the separation between the slits is halved, and (ii) the source slit is moved closer to the double slit? Justify your answer.

Answer:

                (i) Fringe width, \[\beta =\frac{D\lambda }{d}\]. When separation d between the slits is halved, fringe width is doubled. (ii) The fringes became indistinct because the interference patterns due to various parts of the source slit overlap.