3.3.1.2
Polarisation has everyday applications
Wave Types, Polarisation & Stationary Waves — AQA A-Level Physics
Polaroid sunglasses
- Contain vertically oriented polarising filters that block horizontally polarised light.
- Light reflected from horizontal surfaces (water, wet roads) becomes partially horizontally polarised.
- The sunglasses reduce this glare, making objects under water visible more clearly.
TV and radio aerials
- Radio and TV signals are broadcast either horizontally or vertically polarised.
- The receiving aerial must be aligned to match the polarisationThe restriction of oscillations of a transverse wave to a single plane. Only transverse waves can be polarised. of the transmitted signal.
- A horizontal aerial receives horizontally polarised signals; a vertical aerial receives vertically polarised signals.
Polaroid photography
- Polarising filters on cameras reduce glare from reflective surfaces.
- Light from underwater objects is refracted (not reflected) so it is not polarised and passes through the filter.
- The underwater object appears brighter than the surface glare in the photo.