Answer to Question #164406 in Optics for Loveline

Question

   State the conditions which must be full filled if interference fringes are to be observed where two

 beams of light overlap.

        Explain how it is that these conditions are fulfilled in the interference experiment using two slits, as

        in Young s experiment.

Answer 1

2 conditions which must be fullfiled for interference of two fringes to be observed are:

1) Beams of light must be coherent and must be in same phase.

2) beam of light must be monochromatic.

For these conditions to be fullfiled in double slit experiment we use,

Source which produce mono chromatic light which produce single coloured light and also we take very small slits which produce waves of only single phase and hence they are coherent.