What is a Dielectric? (Physics, Electricity)

Without dielectric materials, you probably wouldn’t be able to watch this video! These materials are very common in all the technologies we use everyday. Dielectrics are a class of insulators that can get polarised when subjected to an electric field. We will see in this video how this happens and why such a property is so useful to electrical and electronical application, especially capacitors.

You will learn also tons of concepts like electric susceptibility, permittivity and dielectic constant, that may appear a little obscure at first sight, but when you understand dielectrics, their meaning becomes quite clear!

So… get ready for the deep dive!

Structure of the video: 00:00 Introduction 00:42 What is a dielectric material? (etymology and definition) 02:17 Electric field applied to a conductor (the reason behind Faraday’s cage) 03:49 Electric field applied to a dielectric (introduction to polarization) 07:25 What is electric susceptibility? (polarization by an electric field) 08:01 What is permittivity? 08:24 What is a dielectric constant? 09:00 Uniform electric fields 10:10 What is Capacitance? 10:45 Dielectrics in capacitors 12:17 dielectrics are materials that can store electrical potential energy (Conclusion)

In order to fully grasp the content of this video, the viewer needs to be familiar with the following concepts already presented in a PME video. _ Electric Potentials. For a quick refresher on what is an electric potential, see this YouTube video: https://youtu.be/j3GrOKre__0 _ Electric Fields. For a quick refresher on what is an electric potential, see this YouTube video: https://youtu.be/8VN8MDn4CFA _ Capacitors. For a quick refresher on what is a capacitor and how it works, see this YouTube video: https://youtu.be/4hl3it9ZwkY

The script, the music and the video were produced and presented by Edouard Reny, Ph.D. in solid state chemistry and private tutor in Physical Sciences. For access to great resources that will help you with your studies of high school Physics, visit the "Physics Made Easy" website:https://www.physics-made-easy.com/ Edouard provides one-on-one private tuition in Physics (face to face or by Skype). If you wish to know more about this, or contact Edouard, visit his website: https://www.physics-tutor.nl/.

Other credits Some photographic resources are present in this video under a creative common license CC 4.0 licenses (https://creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons)

• Dielectric coating (in introduction): Zaereth, CC BY-SA 4.0 Cooling - Processes (picture in introduction): Rolf Brink, CC BY-SA 4.0

CC 3.0 licenses (https://creativecommons.org/licenses/by-sa/3.0, via Wikimedia Commons)

• Faraday's cage (the car with the spark): Martin Apolin, CC BY-SA 3.0
• The image of the spring (end of video) was extracted from an image of Svjo, CC BY-SA 3.0 ... https://www.youtube.com/watch?v=4hpLxJYEBHA