Alinearly polarized electromagnetic wave has an average intensity of i0. this wave is incident on a polarizer. what angle between the axis of polarization of the polarizer and the direction of polarization of the incident light will result in an average intensity of light leaving the polarizer of 0.33·i0?

Amichelson interferometer operating at a 600 nm wavelength has a 3.02-cm-long glass cell in one arm. to begin, the air is pumped out of the cell and mirror m2 is adjusted to produce a bright spot at the center of the interference pattern. then a valve is opened and air is slowly admitted into the cell. the index of refraction of air at 1.00 atm pressure is 1.00028.how many bright-dark-bright fringe shifts are observed as the cell fills with air?