Duality (electrical circuits)
In electrical engineering, electrical terms are associated into pairs called duals. A dual of a relationship is formed by interchanging voltage and current in an expression. The dual expression thus produced is of the same form, and the reason that the dual is always a valid statement can be traced to the duality of electricity and magnetism.
Here is a partial list of electrical dualities:
- voltage - current
- parallel - series
- resistance - conductance
- voltage division - current division
- impedance - admittance
- capacitance - inductance
- reactance - susceptance
- short circuit - open circuit
- Kirchhoff's current law - Kirchhoff's voltage law
- Thévenin's theorem - Norton's theorem
History
The use of duality in circuit theory is due to Alexander Russell who published his ideas in 1904.Examples
Constitutive relations
- Resistor and conductor
- Capacitor and inductor - differential form
- Capacitor and inductor - integral form
Impedance and admittance
- Resistor and conductor
- Capacitor and inductor