Question

Monochromatic light is sent through two ideal linear polarizers. Initially, their transmission axes were set to be parallel, and the intensity of light after the two polarizers was measured to be io. Then, for the purpose of all the questions from (a) to (g) below, the second polarizer has been rotated so that its transmission axis now forms a α = 66° angle with that of the first polarizer. What is the intensity of light after the second polarizer?

1) io
2) io/2
3) io/4
4) io/8

Answer 1

The intensity of light after passing through two polarizers set at a 66° angle to each other is io/2, calculated using the law of Malus.

Step-by-step explanation:

The intensity of light after it passes through two ideal linear polarizers with their transmission axes at an angle of α = 66° can be found using the law of Malus, which states that the intensity I of polarized light after passing through a polarizing filter is I = Io cos² α, where Io is the original intensity and α is the angle between the direction of polarization and the axis of the filter. Since the initial intensity is io and the angle is 66°, the equation becomes I = io cos² (66°). Calculating this, we find that the transmitted intensity I is io/2.