question_answer

In Young's double slit experiment if the distance between two slits is halved and distance between the slits and the screen is doubled, then what will be the effect on fringe width?

Answer:

                Original fringe width, \[\beta =\frac{\lambda D}{d}\] New fringe width, \[\beta '=\frac{\lambda .2D}{d/2}=\frac{4\times D}{d}=4\beta \] i.e., fringe width increases four times.