Physics Unpolarized light

Question

Unpolarized light of intensity 600 W/m is incident on two ideal polarizing sheets that are placed with their transmission axes perpendicular to each other. An additional polarizing sheet is then placed between the two, with its transmission axis oriented at 30 to that of the first. 

What is the intensity of the light passing through the stack of polarizing sheets?

What orientation of the middle sheet enables the three-sheet combination to transmit the greatest amount of light?

Answer 1

Two polarizing sheets stacked with perpendicular axis’s of polarization will cause a complete cancellation of light. To achieve maximum intensity you would want ideally no polarization, and if you must, only one sheet or multiple sheets with parallel axis’s.