2.2 Kirchhoff's Laws

• Kirchhoff’s current law (KCL) - The current flowing out of any node in a circuit must equal the current flowing in. That is, the algebraic sum of all branch currents flowing into any node must be zero.
• Kirchhoff’s voltage law (KVL) - The algebraic sum of the branch voltages around any closed path in a network must be zero.
• Voltages across two parallel connected elements must be the same.

2.1 Terminology

• The junction points at which the terminals of two or more elements are connected are referred to as the nodes of a circuit
• The connections between the nodes are referred to as the edges or branches of a circuit
• Circuit loops are defined to be closed paths through a circuit along its branches

• Branch current is the current along a branch of the circuit
• Branch voltage is the potential difference measured across a branch

2.0 Resistive Networks

• Solving or analyzing a circuit generally involves finding the voltage across, and current through, each of the circuit elements
• When circuit obeys the lumped matter discipline, Maxwell's Equations can be simplified into two algebraic relationships stated as Kirchhoff's voltage & current law (KVL & KCL)