What does the principle of superposition state in linear circuits?

The principle of superposition is a fundamental concept in linear circuit analysis, and it specifically states that in a linear circuit with multiple independent sources, the total response (voltage or current) at any point in the circuit is equal to the algebraic sum of the responses produced by each independent source acting alone, while all other independent sources are turned off (deactivated). "Turning off" a source typically means replacing a voltage source with a short circuit and a current source with an open circuit.

This principle is particularly useful in analyzing complex circuits because it allows engineers and technicians to simplify the analysis by breaking it down into more manageable parts. By analyzing the effect of each independent source separately, the overall behavior of the circuit can be determined more easily.

The other options do not accurately represent the principle of superposition. For example, saying that total response is determined solely by initial conditions overlooks the continuous effect of independent sources over time, while suggesting that responses from independent sources are mutually exclusive contradicts the additive nature of their contributions. Additionally, claiming that individual responses cannot be combined ignores the core idea of superposition—that these responses can indeed be combined to determine the total response in the circuit.