Malus's Law

Students can investigate the relationship between the proportion of transmitted light and the angle of rotation of two polarising filters. A graduated cartridge containing two polarising filters allows students to observe the change in intensity as they are rotated relative to one another. The analyser allows quantitative readings to be taken, using a voltmeter, at five degree intervals as the polarising filters are rotated from minimum to maximum transmission.
The output from the analyser changes linearly with light intensity and so the resulting data can be used to verify Malus’s law.