Physics (AS & A Level) · Oct / Nov 2023 · Paper 12 · Question 24

A plane polarised light wave of intensity I₀ is incident normally on a polarising filter. The initial intensity of the transmitted wave is 0. A second polarising filter is then inserted between the source and the first filter. Its transmission axis is at 45° to the transmission axis of the first filter, as shown. What is the intensity of the transmitted wave from the filter combination?

1. A0
2. BI₀/8
3. CI₀/4
4. DI₀/2

As printed in the paper