WAEC Physics 2013 Theory — Question 6

Model answer

(a) A polarizer is an optical device which allows vibrations (of light) to pass through in only one plane, perpendicular to the direction of propagation. (b) The diagram shows unpolarized light (which has vibrations in all directions) passing through a polarizer. A polarizer blocks all vibrations except those in one particular plane, transmitting vibrations in only one plane perpendicular to the direction of propagation — the emerging light is then polarized light, vibrating in a single plane.