PURPOSE: To demonstrate polarization of light.

DESCRIPTION: The first polaroid polarizes the light. Rotating the front polaroid causes the light to become alternately brighter (polaroids aligned) and dimmer (polaroids crossed).

Insert a third polaroid between the two crossed polaroids at a 45 degree angle to show that the electric field is a vector, and to demonstrate a component of a component.

SUGGESTIONS:

EQUIPMENT: Halogen lamp on a stand, large round polaroids monted on a ring stand, extra square polaroid.

SETUP TIME: 15 min.