Thevenin’s theorem states that a linear two- terminal circuit can be replaced by an equivalent circuit consisting of a voltage source Vth in series with a resistor Rth where Vth is the open circuit voltage at the load terminals and Rth is the input or equivalent resistance at the load terminals when the independent sources are turned off. i.e. killed.
- This theorem is applicable only for linear networks i.e. networks with R.L,C, transformer and linear controlled sources as elements.
- Presence of dependent sources makes the network active and hence these theorems are used for both active as well as passive networks.