Electric Current Definition of Current Electromotive Force Ohm’s Laws Joule’s Laws Kirchhoff’s Laws Unsteady-state Processes in a Circuit with Capacitor
Definition of Current I = nSve
Electromotive Force Efficiency of a battery:
Ohm’s Laws - in integral form - in differential form
Joule’s Laws In integral form: In differential form:
Kirchhoff’s Laws (1) The algebraic sum of the currents at a junction of a circuit is zero, (2) The algebraic sum of the potential differences across the resistances is equal to the algebraic sum of the EMFs,
Kirchhoff’s Laws (cont.) The total number of equations (1) for a network is equal to a number of branch points of a network minus one. The total number of equations (2) for a network is equal to the minimum number of ruptures needed to stop the current flow round all loops of a network.
Unsteady-state Processes in a Circuit with Capacitor (1) Charging the capacitor
Unsteady-state Processes in a Circuit with Capacitor (cont.)
Unsteady-state Processes in a Circuit with Capacitor (cont.) (2) Discharging the Capacitor