Two Polaroids are kept crossed to each other. Now one of them is rotated through an angle of 45o The percentage of incident light now transmitted through the system is

According to Mal us lawI=Imcos2⁡θ when light passes through polaroid, only 50% light is  able to pass i.e., Im=I/2 % of incident light transmitted  =I/2cos2⁡45∘I×100 =I/4I×100=1004=25%