Q 12-10-110JEE MainJEE Main 2021 (24 Feb, Shift 2)Easy
If the source of light used in a Young's double slit experiment is changed from red to violet:
Answer: (A) consecutive fringe lines will come closer.
Fringe width $\beta = \dfrac{\lambda D}{d}$. Violet light has a shorter wavelength than red, so $\beta$ decreases and the fringes come closer. The centre stays bright and the minima stay dark.
Solution by Sreeraj P, M.Sc Physics