A Young's double slit experiment is performed with white light.

Options

A. The central fringe will be white
B. There will be no completely dark fringe
C. The fringe next to central fringe will be violet
D. The fringe next to central fringe will be red.

Answer

A, C, D

Explanation

When source is of white light, the central fringe is white as all colours meet there in phase. No fringe is completely dark as some value of `lambda` (colour) may satisfy condition for constructive interference. As `beta prop lambda` and `lambda_(v) lt lambda_( r)`, therefore, the fringe next to central fringe will be violet.