# Superposition Theorem Notes

This theorem is applicable for linear and bilateral networks. Let us see the statement of the theorem.

**Statement**: In any multisource complex network consisting of linear bilateral elements, the voltage across or current through any given element of the network

is equal to the algebraic sum of the individual voltages or currents, produced independently across or in that element by each source acting independently, when

all the remaining sources are replaced by their respective internal resistances.

If the internal resistances of the sources are unknown then the independent voltage sources must be replaced by short circuit while the independent current sources

must be replaced by an open circuit.

**Steps to Apply Superposition Theorem**

Step 1: Select a single source acting alone. Short the other voltage sources and open the current sources, if internal resistances are not known. If known, replace them by their internal resistances.

Step 2: Find the current through or the voltage across the required element, due to the source under consideration, using a suitable network simplification technique.

Step 3: Repeat the above two steps for all the sources

Step 4: Add the individual effects produced by individual sources, to obtain the

total current in or voltage across the element