when solving a RL or RC circuit, what's the easiest way to tell if it is a natural response problem or step response?
James W. Nilsson, Electric Circuits, 2nd Ed, 1985.In the case of a parallel RLC circuit, the natural response consists of finding the voltage across the parallel branches that arises due to the release of energy that has been stored in the inductor, capacitor or both. The step response of a parallel RLC circuit implies finding the voltage that appears across the parallel branches as a result of a sudden application of a dc, or constant, current source.
The natural response of a series RLC circuit consists of finding the current in the series-connected elements that arises due to the release of stored energy in either the inductor, capacitor or both. The step response of series RLC circuit implies finding the current in the series-connected components when a sudden dc voltage is applied.