If a torch is used in place of monochromatic light in Young's experiment what will happen?

Options

A. Fringe will appear for a moment then it will disappear
B. Fringes will occur as from monochromatic light
C. Only bright fringes will appear
D. No fringe will appear

Answer

D

Explanation

No fringe will appear, when we use torch in place of monochromatic light because waves reaching at any point on the screen do not have a constant phase difference, as phase difference due to different colours changes randomly. Therefore, maxima and minima would also change their positions randomly and in quick auccession. This will result in general illumination on the screen.