The following items are positioned in sequence: A source of a beam of natural light of intensity $I _ { 0 }$, three ideal polarizers A, B, and $\mathrm { C }$; and an observer. Polarizer axis angles are measured clockwise from the vertical, as viewed by the observer. The axis angle of polarizer $\mathrm { A }$ is set at $0 ^ { \circ }$ (vertical), and the axis angle of polarizer $C$ is set at $50 ^ { \circ }$. Polarizer $B$ is set so that the beam intensity at the observer is a maximum. What is the axis angle settings of polarizer B?

Question

Quizplus · Accepted Answer

To maximize the intensity of the beam at the observer, polarizer B should be set at an angle that is halfway between the angles of polarizers A and C. Since A is at $0^\circ$ and C is at $50^\circ$, the optimal angle for B is $25^\circ$, which is halfway between $0^\circ$ and $50^\circ$. This maximizes the transmitted intensity through the sequence of polarizers.

The Following Items Are Positioned in Sequence: a Source of a Beam