Q 12-09-206JEE MainJEE Main 2019 (11 Jan, Shift 1)Easy
The variation of refractive index of a crown glass thin prism with wavelength of the incident light is shown. Which of the following graphs is the correct one, if $D_m$ is the angle of minimum deviation?
Answer: (A) see figure
For a thin prism $D_m = (n - 1)A$, so $D_m$ follows the shape of the $n$–$\lambda$ graph.
$n$ decreases with $\lambda$, steeply at first and then more slowly, so $D_m$ also decreases with $\lambda$ along a similar curve: graph (1).
Solution by Sreeraj P, M.Sc Physics