Domestic appliances.
The emphasis in this topic is to understand everyday electrical devices in term of the physics involved in their operation. Your students will be able to do this provided that you continue to use good examples that they can relate to. Try this video clip to start your lessons on domestic appliances.
In looking at energy transfers be careful to keep it relevant. Having a collection of mains items such as a hairdryer, a radio, a kettle, a toaster and a desk lamp that you can pull out to make a point will be useful.
You also need to explain the whole national grid supply system from the power station, through the use of transformers to the end users, us. This video clip is excellent for doing the job.
Your students will need their math skills for using the equations relating p.d., current, power, energy, and time, to solve problems on energy transfer.
Whilst this list provides a source of information and ideas for experimental work, it is important to note that recommendations can date very quickly. Do NOT follow suggestions which conflict with current advice from CLEAPSS, SSERC or recent safety guides. eLibrary users are responsible for ensuring that any activity, including practical work, which they carry out is consistent with current regulations related to Health and Safety and that they carry an appropriate risk assessment. Further information is provided in our Health and Safety guidance.
Electrical Safety *suitable for home teaching*
This article provides a lot of information related to safe use of mains appliances. The safety measures outlined here in compliance with the legislation have significantly reduced accidents and harm done by unsafe practice in recent years. You can use it as a resource with your students for them to prepare for group discussion on the issue of safe practice.
UK Mains plug
Use this revision material as the basis of a summary note on UK mains wiring and the three pin plug. As an activity you can show the correct wiring of a plug. All you require are a box of plugs, a box of screwdrivers and a few metres of cable. On a safety note for this activity, when you cut lengths of cable to use with the plugs make sure that you pull the inner cores out of the outer insulation by a few centimetres so none of the inner cores are exposed at the end not attached to the plug. Isolating the power to the sockets before doing this activity is another precaution to take.
Episode 106: Electrical Power
From the Institute of Physics, in this learning episode, students calculate electrical power and through discussion, review their understanding of current, potential difference, electromotive force (emf), charge and drift velocity. Students are reminded of the idea that power is the rate of doing work (or the rate at which energy is transferred). A range of calculations allow students to explore the relationships between electrical power, current, voltage, resistance and energy transfer.
Power Lines
In this video the case for showing this demonstration as well as advice on safe practice for carrying it out is given. If you don’t usually do this experiment, hopefully seeing it demonstrated so well, will encourage you to start doing so. Students’ seeing this demonstrated to them makes all the difference to their understanding of the need for transformers in power distribution.
Case Study: Electrical Installation *suitable for home teaching*
You could show this video to your students to encourage them to consider a career as an electrical engineer. Those of them who are getting to grips with the topic will like to know that they could use their growing understanding to have a very rewarding future in this profession.
Transformers
An informative YouTube video discussing how transformers operate. The clip has very clear visualisation of the inner workings of the transformer and a good description to accompany what is shown on the screen.