Question

What change occurs, if the monochromatic light used in Young's double slit experiment is replaced by white light?

• A. Only the central fringe is white and all other fringes are observed coloured
• B. No fringes are observed
• C. All the bright fringes become white.
• D. All the bright fringes are coloured between violet and red

Answer 1

The correct option is A Only the central fringe is white and all other fringes are observed coloured

When we use white light in place of monochromatic light then only central fringe looks white and other fringes of different colour are observed. It is becaused central fringe for all the colours are formed at central point so it becomes white after mixiing up. As fringes of other colours fall at different places we see fringes of all colour on the central bright fringe.