The lumped element model of electronic circuitss makes the simplifying assumption that each element is an infinitesimal point in space, and that the wires connecting elements are perfect conductorss.
This is reasonable for many actual circuits, but breaks down when actual circuit impedances are very low, or when the length of the wire approaches the wavelength of the circuit's operating frequency.
When this happens we must consider a more general model. Real-world components exhibit non-ideal characteristics. To account for leakage in capacitors for example, we can visualize the capacitor as having a large resistor connected in-parallel. Similarly to account for inductive reactance, we can visualize component leads as small inductors.
Contrast: Distributed element model.
External links:
