1. Voltage This is basically the force that 'pushes' electrons around a circuit...ie gives them energy. A voltmeter measures the difference in energy between 2 points in a circuit Always wired in parallel

2. Current This is the flow of electrons around a circuit... (like the current in a river) Measured in Amps 1 Amp = 1 coulomb of electrons per second (a coulomb = 6 x 1018) (think of a coulomb as a 'bunch') Always wired in series

3. So we wire them like this

4. Power This is the rate at which electrical energy is used. Power = Volts x Amps P = V I Way you go then....measure something! Don't forget that P also = E / t (same formula as our force / motion topic)

5. Resistance This is the measure of how much something opposes the flow of electrons (ie opposes current) Volts = Current x Resistance V = I R or with a wee bit of algebra…. R = V / I Resistance is measured in ohms, symbol: Ω

6. Diodes sneaky wee current controllers... they allow current to flow in one direction but not the other. Some produce light when current flows through them, these are LED's Where does the current go then?