Physics (AS & A Level) · Oct / Nov 2025 · Paper 13 · Question 26

Two polarising filters are placed next to each other so that their planes are parallel. The first polarising filter has its transmission axis at an angle of 50° to the vertical. The second polarising filter has its transmission axis at an angle of 20° to the vertical. The angle between the transmission axes of the two polarising filters is 30°. A beam of vertically polarised light of intensity 8.0 W m⁻² is incident normally on the first polarising filter. What is the intensity of the light that is transmitted from the second polarising filter?

1. Azero
2. B2.5 W m⁻²
3. C2.9 W m⁻²
4. D6.0 W m⁻²

As printed in the paper