a) Discuss Rayleigh’s criterion for resolving power of an optical instrument. Obtain an
expression for the resolving power of a microscope.?
b) A He-Ne laser emits a beam of diameter 2×10^−3m and wavelength 630 nm. It is directed
towards an aeroplane flying at a height of 11 km. Calculate the diameter of the light patch
produced on the surface of the aeroplane.?