Solving a Simple Circuit of Three Elements

A simple circuit is solved and power absorbed or supplied by each element is determined. KCL as well as Ohm's law are used in solving the circuit. positive sign convention is used in determining element powers. It is shown and discussed how a source, here current source, can be neither absorbing or supplying power. It is also mentioned that resistors are passive elements and always absorb power/energy.

Nodal Analysis - Circuit with Dependent Voltage Source

A 6-node circuit is solved with the nodal analysis. It contains one dependent voltage source, two independent voltage sources, two independent current sources and some resistors. The dependent causes two nodes to form a supernode.