In Young's double slit experiment, we get 60 fringes in the field of view if we use light of wavelen

Question

In Young's double slit experiment, we get 60 fringes in the field of view if we use light of wavelength $4000 \AA$. The number of fringes we will get in the same field of view if we use light of wavelength $6000 \AA$ is

Professor PC Thomas Classes · Answer

Interference involves the superposition of coherent waves. The fringe width is $\beta = \frac{\lambda D}{d}$. Based on the conditions, the correct answer is A.