In the Young's double slit experiment, the intensity of light at a point on the screen where the path difference $$\lambda $$ is K, ($$\lambda $$ being the wavelength of light used). The intensity at a point where the path difference is $$\lambda $$/4 will be

In Young's double slit experiment the distance between the slits and the screen is doubled. The separation between the slits is reduced to half. As a result the fringe width

A parallel beam of light of wavelength $$\lambda $$ is incident normally on a narrow slit. A diffraction pattern formed on a screen placed perpenficular to the direction of the incident beam. At the second minimum of the diffraction pattern, the phase difference between the rays coming from the two edges of slit is

The reddish appearance of the sun at sunrise and sunset is due to