Charge and current

• Electrical current = the rate of flow of charge
• 1 Amp = 1 Coulomb per second
• Kirchoff’s first law = the total current entering a junction is equal to the total current leaving the junction
• Conventional current = positive to negative

  Electron flow = negative to positive
• The better conductor = higher number density = more electrons
• Charge carries move by electrons colliding repeatedly with (+) ions as they drift towards the (+) terminal
• When the CSA of a wire decreases, the mean drift velocity increases for the current to be the same