Describe Young's double slit experiment and determine the conditions for obtaining bright and dark fringes.

Describe Milikan's oil drop experiment to determine the charge of an electron.

A beam of light consisting of two wavelengths 6500 A ˙ and 5200 A ˙ is used to obtain fringes in a Young's double slit experiment.Find the distance of the third bright fringe on the screen from central maximum for the wavelength 6500 A. The distance between the slits is 2mm and the distance between the plane of the slits and the screen is 120 cm

In a Young's double slit experiment distance between the slits is 1 mm. The fringe width is found to be 0.6 mm. When the screen is moved through a distance of 0.25 m away from the plane of the slit, the fringe width becomes 0.75 mm. Find the wavelength of light used.

What is the effect on the interference fringes in Young's double slit experiment when the monochromatic source is replaced by a source of white light?