1. Current and Voltage

2. Current Flow rate of electricity Current flows from + to – Measured in Amps – 1 Amp = 1 Coulomb per second Actually electrons flow in the opposite direction Many electrons make up one coulomb of charge All the current flow rate around a circuit is the same. (Current in branches adds up to equal the total current (exception! = capacitors)

3. Voltage 1 Volt is 1 Joule per Coulomb It is the energy transfer to or from a coulomb of charge Electro-motive force (EMF) The work done on (energy transferred to) a coulomb of charge by a battery or power supply Potential Difference The energy level difference between two places Voltage and current The greater the potential difference between two places the higher the current. The ratio voltage:current is resistance ( V = IR ) P = VI