Two polaroid sheets are arranged so that their transmission axes are at 90 degrees to each other.
(a) If a beam of unpolarized light of intensity 100 W/m2 is incident on the first sheet what is the intensity of the light leaving the second sheet?
(b) A third polaroid sheet with its transmission axis oriented 45 degrees to the first sheet is inserted between the two sheets. What is the intensity of light leaving the final sheet now?