Note: for a more in-depth look at circuits, see here!

So, you know all you need to know about circuits, but you’re a bit stuck for how to explain it? Take a look at this simple definitions to help you along:

  • Potential Difference: The amount of energy transferred per coulomb of charge.
  • Current: The flow of electrons in a circuit (they flow from negative terminals to positive terminals!)
  • Resistance: This happens when an electron collides with an atom, and causes heat.

And here’s some helpful things to remember:

Series Circuits:

  • Current stays the same in a series circuit (as the electrons can only go one way)
  • Potential Difference is shared in a series circuit. (Thanks to different resistances)

Parallel Circuits:

  • Current is shared in a parallel circuit (like a fork in the river). The electrons are able to go two or more ways.
  • Potential Difference is the same in a parallel circuit (as the potential difference will always add up again at the ‘end’ of the circuit.

So really, they’re just opposites!


UK Plug Wiring

So, this is it people. After this post, you’ll be able to read and understand the whole AQA P2 Physics specification without ever leaving Revision Systems! It’s taken a lot of words for us to get to this point, but hopefully you’ll find it useful. So, here we go. On this final stretch we’ll be looking at:

  • Plugs (and their wiring, as seen above)
  • Power
  • The dangers of electricity (although these are fairly obvious, so we won’t go into too much detail.)

So, let’s go!

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A/C Oscilloscope Trace

Above this paragraph is a bog-standard oscilloscope trace, from an alternating current (AC) power source. Unfortunately, in the exam, you might be asked to do a bit more than simply look at an oscilloscope trace. That’s why in this article, we’re going to cover what an oscilloscope trace is, what AC and DC are, and the differences between the two.

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Fuse Circuit Symbol

So, what is a fuse? What’s a circuit breaker? How does a fuse work? What’s the difference?! All of these are very relevant questions, and thankfully, all of them are relatively simple to answer, too. For the P2 exam, you need to know what a circuit breaker is, what a fuse is, how they work, when we use them, why we use them, and some advantages and disadvantages. So… Do you have some popcorn? Are you comfortable? If the answer to any of the previous two questions was ‘no’, then you might want to fix that and come back straight away!

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Current electricity and calculations involving electricity within different types of circuit are important for P2 – so of course, we’re going to cover it here. Ready? Then let’s dive into the wonderful world of electricity…

Note: Check out Ben’s article on circuit symbols here for a supplementary article:

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Plum Pudding Model

Ah, the pretty looking plum-pudding model. The pretty looking wrong plum pudding model, that should be. Indeed, originally thought to be the pinnacle of scientific discovery, it all fell apart horribly for physics one day in 1909. Join me on this tale of woe, as we discover why physicists were wrong for years about how atomic structure looks.

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Image (C) NASA

So, after the informative guide on nuclear fission, there was only one natural follow-up, right? Don’t worry: this one will be somewhat shorter. There’s not really much to say on nuclear fusion, we can’t properly use it, after all – still: it’s a topic that’s probable to come up, and at the end of the day, there are more boring things that you could be revising – so hey? What do you have to lose?

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