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# Basic Electricity Rules - Help Needed. watch

1. Okay so I got my AQA A AS Physics Unit 1 exam coming up. The topics are Particles, Quantum Phenomena & Electricity.

I'm fine with the other two topics but I find electricity a nightmare and I think where I go wrong is the foundation.

What rules do I need to know for electricity (the basic ones, most likely from iGCSE Physics)

All I know is the resistors in parallel and series rules and the three kirchoff laws. Are there anymore that I should know?

Is there any more rules to do with current, voltage etc?
2. (Original post by Slenderman)
Okay so I got my AQA A AS Physics Unit 1 exam coming up. The topics are Particles, Quantum Phenomena & Electricity.

I'm fine with the other two topics but I find electricity a nightmare and I think where I go wrong is the foundation.

What rules do I need to know for electricity (the basic ones, most likely from iGCSE Physics)

All I know is the resistors in parallel and series rules and the three kirchoff laws. Are there anymore that I should know?

Is there any more rules to do with current, voltage etc?
Voltage is the same on each branch of a parallel circuit. In series, say if you have a 10ohm resistor and a 15ohm resistor, and a 10V supply, to work out the potential difference across the 10ohm resistor, you do 10/the total resistance in this case, 10/25 and then * by 10. So the 10ohm resistor has a pd of 4V and the pd across the 15ohm resistor will be 6V as V1+V2 must equal V0.

I will pm you the current rules if you want?
3. (Original post by particlestudent)
Voltage is the same on each branch of a parallel circuit. In series, say if you have a 10ohm resistor and a 15ohm resistor, and a 10V supply, to work out the potential difference across the 10ohm resistor, you do 10/the total resistance in this case, 10/25 and then * by 10. So the 10ohm resistor has a pd of 4V and the pd across the 15ohm resistor will be 6V as V1+V2 must equal V0. I will pm you the current rules if you want?
Yes please mate. So will this work for any circuit?
4. Some of this may help:

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