Q 12-10-007NEETNEET 2020Top questionEasy
In Young's double slit experiment, if the separation between coherent sources is halved and the distance of the screen from the coherent sources is doubled, then the fringe width becomes :
Answer: (C) four times
Concept. Fringe width $\beta = \dfrac{\lambda D}{d}$.
Step 1. New width.
$$\beta' = \frac{\lambda(2D)}{d/2} = 4\beta$$
Answer. Four times (Option C).
Solution by Sreeraj P, M.Sc Physics