Question

how do you find the angle between two polarizers? Also, on this question i am working on it says the marks on the second polarizer lie along a line with a 2 degree angle to the horizontal, what does this exactly mean?

Answer 1

Measure the intensity of the incident light without any polarizers.

Now introduce the first polarizer and measure the new intensity. If the light used is unpolarized, this new intensity will drop to half of its initial value. Call this intensity I_o. Now introduce 2nd polarizer and measure the new intensity at the detector I.

Using Malus' law, , determine the angle between the two polarizers.

The statement "the marks on the second polarizer lie along a line with a 2^o angle to the horizontal" essentially means that the readings on the polarizers are not properly indented and are at angle of 2^o from the horizontal 0^o axis. So, any measurement made must account for this zero error by subtracting 2^o from the obtained angle.