Question

In which case superposition theorem is not applicable?

Answer 1

The Superposition Theorem is not applicable in the following cases:

1. Non-linear circuits: The Superposition Theorem only works for linear circuits. In circuits where components like diodes, transistors, or other non-linear elements are present, the relationship between voltage and current is not linear. This makes the application of the Superposition Theorem invalid.
   

1. Dependent sources: If a circuit has dependent sources (also called controlled sources), the Superposition Theorem might not directly apply. The behavior of dependent sources depends on other variables in the circuit, which complicates applying the superposition principle in a straightforward manner.
   

1. Power calculation: The Superposition Theorem is only valid for calculating voltage and current in the circuit. It doesn't directly apply when trying to find power dissipation in a resistor or power delivered by a source because power depends on both the magnitude and the phase of voltage and current, which isn't correctly handled by simply adding the effects of individual sources.
   

In short, Superposition works best for linear circuits with independent sources, but should not be used in circuits with non-linear components or dependent sources, or for power calculations.