In Young’s double-slit experiment, lights of green, yellow, and

in-youngs-double-slit-experiment-lights-of-green-yellow-and

In Young’s double-slit experiment, lights of green, yellow, and orange colors are successively used. Write the fringe widths for the three colors in increasing order.

A. βG < βY < βO

B. βO < βY < βG

C. βO < βG < βY

D. βY < βG < βO

The question was posed to me during a job interview.

This intriguing question comes from Wave Optics topic in chapter Wave Optics of Physics – Class 12

The correct option is B. βO < βY < βG

To explain: Fringe width is expressed as:

β = \(\frac {D\lambda }{d}\).

Since the wavelength are related as shown ➔ λG < λY < λO, we can say that ➔ βG < βY < βO.