Derive an expression for path difference in Young' s double slite experiment and obtain the conditions for constructive and destructive inteference at a point on the screen.

(i) In Young's double slit experiment the condition for (a) constructive and (b ) destructive interference at a point on the screen .

In Young's double slit experiment derive the condition for (i) constructive interference and (ii) destructive interference at a point on the screen.

Derive an expression for the bandwidth in Young's double slit experiment.

Answer the following: (a) In Young's double slit experiment, derive the condition for (i) constructive interference and (ii) destructive interference at a point on the screen. (b) A beam of light consisting of two wavelengths, 800 nm and 600 nm is used to obtain the interference fringes in a Young's double slit experiment on a screen placed 1.4 m away. If the two slits are separated by 0.28 mm, calculate the least distance from the central bright maximum where the bright fringes of the two wavelengths coincide.