State two conditions required for obtaining coherent sources. In Young.s arrangement to produce interference pattern, show that dark and bright fringes appearing on the screen are equally spaced.

Define the term' coherent sources' which are required to produce interference pattern in Young's double slit experiment.

A beam of light consisting of two wavelengths, 650 nm and 520 nm, is used to obtain interference fringes in a Young's double-slit experiment. (a) Find the distance of the third bright fringe on the screen from the central maximum for wavelength 650 nm. (b) What is the least distance from the central maximum where the bright fringes due to both the wavelengths coincide?The distance between the two slits is 0.28mm and the screen is at a distance of 1.4m from the slits

Interference fringes are obtained using two coherent sources whose intensities are in the ratio 4 : 1. Then the ratio of the intensities of the bright and dark bands is

In a Young’s double slit experiment, the slits separated by 1 mm are illuminated by a mixture of two wavelengths lambda = 600 nm and lambda' = 750 nm . The distance of screen from slits is 1 m. The minimum distance from the common central bright fringe where the bright fringe of one interference pattern will coincide with the bright fringe of second interference pattern will be :