What is Polarised Light? (Polarisation Part 1 - Waves - Physics)

Light can be Polarised. What does it mean? In this video, I use the wave representation of light to explain what makes a ray of light polarised. Then, I propose a description of what is unpolarised light. After this, I explain how unpolarised light can be polarised using a Polariser.

This does not only apply to light. Mechanical (transversal) waves can be polarised too. To demonstrate that, I improvise an experiment with what I find in my house…

And what about when the incident light entering a polariser is already polarised. I show you on the white board the effect of the polariser on the amplitude and plane of oscillation of the light.

This last section will be the starting point for the next episode, where I will derive and show you how to apply Malus’ law. Malus' law deals with how a Polariser modifies the energy carried by light.

The video is concluded in an example of what could be answered at the exam question: “define what is polarised light”.

00:15 What is polarised light? 01:53 What is unpolarised light? 02:50 Effect of a polariser on unpolarised light. 03:45 Polarisation of a mechanical wave (demonstration). 05:54 Effect of a Polariser of incident polarised light. 07:30 What is polarised light? What to answer at an exam?

This video is produced and presented by Edouard Reny, Ph.D. in solid state chemistry and private tutor in Physical Sciences.

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Edouard provides one-on-one private tuition in Physics (face to face or by Skype). If you wish to contact him, visit his website: https://www.physics-tutor.nl/