Devices
- Capacitors:
Purpose is to store charge (energy).
- We have calculated the capacitance of a system
- We had to modify Gauss' Law to account for bulk matter effects (dielectrics) … C = kC0
- We calculated effective capacitance of series or parallel combinations of capacitors
- Batteries (Voltage sources, seats of emf):
Purpose is to provide a constant potential difference between 2 points.
- Cannot calculate the potential difference from first principles.. electrical « chemical energy conversion. Non-ideal batteries will be dealt with in terms of an "internal resistance".