Q 12-10-045JEE MainJEE Main 2025 (22 Jan, Shift 2)Easy
Given below are two statements. One is labelled as Assertion (A) and the other is labelled as Reason (R).
**Assertion (A):** In Young's double slit experiment, the fringes produced by red light are closer as compared to those produced by blue light.
**Reason (R):** The fringe width is directly proportional to the wavelength of light.
In the light of the above statements, choose the correct answer from the options given below:
Answer: (D) (A) is false but (R) is true
Fringe width $\beta = \dfrac{\lambda D}{d} \propto \lambda$, so (R) is true.
Red light has a longer wavelength than blue, so red fringes are **wider** apart, not closer. (A) is false.
Solution by Sreeraj P, M.Sc Physics