# Physics - Polarisation

> Source: https://ollybritton.com/notes/a-level/physics/topics/polarisation/ · Updated: 2021-03-18 · Tags: physics, waves, school, year-1

## See Also
- [Physics - Reflection and Refraction](https://ollybritton.com/notes/a-level/physics/topics/reflection-and-refraction/)
- [Physics - Waves](https://ollybritton.com/notes/a-level/physics/topics/waves/)
- [Physics - Diffraction](https://ollybritton.com/notes/a-level/physics/topics/diffraction/)
- [Physics - Intensity](https://ollybritton.com/notes/a-level/physics/topics/intensity/)

## Flashcards
##### What is polarisation??
Where particles in a wave are oscillating in one direction only.

##### What does it mean for a wave to be plane polarised??
Where the particles in the wave are oscillating along a single plane.

##### What does it mean for a wave to be partially polarised??
Where most of the particles in a wave are oscillating along a single plane.

##### What does a polarising filter do??
Only allow oscillations that are in a certain direction.

##### What is an example of unpolarised light??
* Light bulb
* Candle light

##### Why can't you polarise a sound wave??
Because you can't polarise a longitudinal wave.

##### What are some examples of how light can become polarised??
* Reflection off water
* Reflection off glass

##### ![PHOTO POLARISATION](polarisation.png) What process does this show??
Polarisation.

### 2022-05-10
##### What is confusing about the polarisation of electromagnetic waves??
It is the opposite to what you'd expect.

##### Why is the polarisation of electromagnetic waves opposite to what you would expect??
Because the waves are absorbed when they cause charges going up and down the filter.

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