When a wave is reflected from a denser medium, the change in phase is:

When light travels from a rarer to denser medium,the speed decreases.Does the decrease in speed imply a decrease in the energy carried by the light wave?Justify you answer.

Equation of a plane progressive wave is given by y=0.6sin 2pi(t-x/2) .On reflection from a denser medium its amplitude becomes 2/3 of the ampliude of the incident wave. The equation of the reflected wave is:

What is an unpolarised ligth ?Explain with the help of a suitable ray diagram,how an unpolarised light can be polarised by reflection from a transparent medium.Write the expression for Brewster angle in terms of the refractive index of the denser medium.