Energy Use In Electrical Appliances | Energy | Physics | FuseSchool

Click here to see more videos: CREDITS Animation & Design: Reshenda Wakefield Narration: Dale Bennett Script: Bethan Parry Do you ever have arguments at home about leaving appliances on and wasting electricity? In this video, we are going to look at measuring energy use, in electrical appliances. The unit of energy is the Joule (J). However, when dealing with electricity, we actually use Watts (W). A Watt is a measure of power where 1 Watt is equal to 1 Joule per second. So a 100W light bulb uses 100J of energy every second. An electrical device will have a power rating. This is the amount of electrical energy the device needs to work. We can calculate how much electrical energy a device transfers by multiplying the power rating (W) by the amount of time the device is on for (in hours). The unit of electrical energy transferred is the Watt Hour (Wh). This is likely to be a very large number, so we usually give the number as kilowatt-hours where 1kilowatt hour is equal to 1000 Watt-hours. Let’s look at an example. A computer has a power rating of 250W. If it is used for 6 hours how much energy is transferred to it? Can you substitute the values into our equation? So how much would that cost to use? To work this out we have to know how much a kWh costs. This differs between different countries, different companies within a country, and even different tariffs from the same company. A whole office of computers. The price starts to clock up quite quickly, and that’s before we think about the lights and charging our phones. VISIT us at, where all of our videos are carefully organised into topics and specific orders, and to see what else we have on offer. Comment, like and share with other learners. You can both ask and answer questions, and teachers will get back to you. These videos can be used in a flipped classroom model or as a revision aid. Access a deeper Learning Experience in the FuseSchool platform and app: This Open Educational Resource is free of charge, under a Creative Commons License: Attribution-NonCommercial CC BY-NC ( View License Deed: ). You are allowed to download the video for nonprofit, educational use. If you would like to modify the video, please contact us:

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