A beam of linearly polarised light of intensity I is incident on an analyser. If the intensity of the transmitted light is measured to be I 4 , what is the angle between the transmission axis of the analyser and the plane of polarisation of the incident light?

Step-by-step solution

According to Malus's law, the intensity of transmitted light is given by: I' = I ^2 Given that the transmitted intensity is I' = I 4 , we can substitute this into the equation: I 4 = I ^2 ^2 = 1 4 = 1 2 The angle whose cosine is 1 2 is 60^ . Choosing 30^ is a common mistake resulting from using sine instead of cosine, and 45^ comes from incorrectly evaluating the inverse trigonometric function. Answer: 60^