Like Thevenin's theorem, Norton's theorem provides a method of reducing a more complex circuit to a simpler, more manageable form for analysis.

The superposition theorem is useful for the analysis of single-source circuits.

Thevenin's theorem provides a method for the reduction of any ac circuit to an equivalent form consisting of an equivalent current source in parallel with an equivalent impedance.

In order to get maximum power transfer from a capacitive source, the load must have an impedance that is the complex conjugate of the source impedance.

In an ac circuit, power to the load peaks at the frequency at which the load impedance is the complex conjugate of the output impedance.