Intensity of a light beam can be defined as amount of light energy incident in unit time on a unit area held normal to the direction of beam. A light beam of intensity I0 has a circular cross section of diameter d0 . This beam is travelling in a medium of refractive index μ=2 and gets incident on the medium-air boundary at an angle of incidence i=30∘ . Assume that entire light energy gets transmitted into air. Find the intensity (I) of transmitted light beam.