The wavelength of the electromagnetic wave used for AM broadcasting is 110 m.

Calculate the frequency of the wave.

A thin film of glass of refractive index 1.5 is inserted in one arm of Michelson Interferometer. Calculate the thickness of the film if a shift of 10 fringes is observed. The wavelength of the light used is 589 nm.

With a labelled diagram, discuss the recording a hologram

Derive an expression to show that the condition of population inversion is necessary

for laser action.

Unpolarised light is incident on two polarizing sheets placed over one another. The intensity of light transmitted finally is one-third of the intensity of the incident light. Calculate the angle between the transmission axes of the two polarizing sheets.

State Fermat’s principle. On the basis of this principle, show that when light passes from a medium of lower refractive index to a medium of higher refractive index, it

bends towards the normal to the interface between the two media.

What is a zone plate? How does a positive zone plate differ from a negative zone plate? Show that each Fresnel half period zone has nearly the same area