Thevenin's theorem is a principle in circuit analysis that states that any linear, active network containing voltage and current sources can be replaced by an equivalent circuit consisting of a single voltage source in series with a single resistor.
Norton's theorem is a principle in circuit analysis that states that any linear, active network containing voltage and current sources can be replaced by an equivalent circuit consisting of a single current source in parallel with a single resistor.
The main difference between Thevenin and Norton equivalent circuits is the type of equivalent source used. Thevenin equivalent circuits use a voltage source, while Norton equivalent circuits use a current source. Additionally, the equivalent resistance in a Thevenin circuit is in series with the source, while in a Norton circuit, it is in parallel with the source.
The Thevenin equivalent resistance is calculated by removing the load resistor from the original circuit and finding the equivalent resistance between the open terminals. This can be done using Ohm's law, by calculating the total resistance of the circuit or by using the voltage and current sources in the circuit.
No, Thevenin and Norton equivalent circuits can only be used for linear circuits. Non-linear circuits, which include components such as diodes and transistors, do not follow Ohm's law and therefore cannot be reduced to a single equivalent source and resistor.