The answer to part 1 is zero.
Sheet Polaroid has inherent losses of about 50%, even for the favored plane of polarization. Therefore I have no further comment about part 2 of your question. Their answer will be wrong. Some light will get through because the polarizer in the middle repolarizes the light.
Two sheets of polaroid are arranged with their polarisation axes at angles of 0 and
90 degrees relative to the horizontal. Randomly polarized light is shone so that it
passes through both filters. What fraction of the light is transmitted?
A further, third sheet of polaroid is now introduced between them with its polarisation
axis at an angle θ to the horizontal. What fraction of the original light intensity now
passes through this arrangement?
What is the maximum possible transmitted fraction?
1 answer