Often it is true in physics that if you can understand one thing then it will automatically help you to understand something else. A good example of this occurs in resistance, where the model of resistance in a wire links directly to the behaviour of circuits that have resistors arranged either in series or in … Continue reading Resistance theory
Online Circuit Simulators
One of the best ways to learn about circuits and resistance is by building circuits - either in the classroom or using an online simulation. I've previously recommended PhET DC Circuit simulation, which (despite some non-standard circuit symbols) is still a great way to take measurements that demonstrate concepts such as Ohm's Law. You can … Continue reading Online Circuit Simulators
Correct wiring of a 3-pin plug
There once was a time when the ability to wire a 3-pin plug was an essential skill - but not any more. For reasons of safety, many devices are now fitted with molded plugs that cannot be opened or removed. Nevertheless, the exam board still expects you to be able to identify the essential features … Continue reading Correct wiring of a 3-pin plug
DC and AC Electricity Pt1: Electron Movement
One of the most famous technological "wars" was the battle that raged almost 150 years ago between Thomas Edison's DC electricity and Nikola Tesla's AC electricity. For our purposes, we will put aside the stories of the two men (Edison was an inventor and businessman whereas Tesla was a scientist and idealist) and focus on … Continue reading DC and AC Electricity Pt1: Electron Movement
Electrical Circuits: mini-test
It is really important that you check your understanding as you work through a topic. With that in mind, I have created a short online test that you can use to check your recall and understanding of some of the basic knowledge required for the Electricity module. You can access the test, which is hosted … Continue reading Electrical Circuits: mini-test
Current and Voltage rules
There is a clear pattern to the measurements of current and potential difference (voltage) in electrical circuits - which, for us, means series and parallel circuits. These two patterns were identified by Gustav Kirchhoff and are therefore known as Kirchhoff's Laws. Kirchhoff's current law states that the sum of the currents flowing into a junction … Continue reading Current and Voltage rules
Circuit Simulation
The excellent circuit simulation that we explored in our lessons is freely available for you to use as part of your independent learning. It was created by the University of Colorado and can be accessed here (or just search for PhET DC simulation). There are, however, a couple of points that you must remember when … Continue reading Circuit Simulation
Mr Tarrant's physbang 'blog 