The electromagnetic waves travel in a medium at a speed of 2.0 $$\times$$ 10⁸ m/s. The relative permeability of the medium is 1.0. The relative permittivity of the medium will be :

The interference pattern is obtained with two coherent light sources of intensity ratio 4 : 1. And the ratio $${{{I_{\max }} + {I_{\min }}} \over {{I_{\max }} - {I_{\min }}}}$$ is $${5 \over x}$$. Then, the value of x will be equal to :

A light whose electric field vectors are completely removed by using a good polaroid, allowed to incident on the surface of the prism at Brewster's angle. Choose the most suitable option for the phenomenon related to the prism.

A proton, a neutron, an electron and an $$\alpha$$ particle have same energy. If $$\lambda$$_p, $$\lambda$$_n, $$\lambda$$_e and $$\lambda$$_a are the de Broglie's wavelengths of proton, neutron, electron and $$\alpha$$ particle respectively, then choose the correct relation from the following :