What does Kirchhoff's Voltage Law (KVL) state?

Kirchhoff's Voltage Law (KVL) is a fundamental principle in electrical engineering that states the sum of the electromotive forces (emf) and potential differences (voltages) in any closed loop of a circuit must equal zero. This can be understood through the law of energy conservation, which indicates that the energy supplied in the form of voltage must be equal to the energy consumed or dissipated in the resistive elements of the circuit (like resistors) as you traverse the loop.

In practical terms, KVL implies that as you move around a closed circuit, the gains in voltage from sources (like batteries) must balance out the drops in voltage across components (like resistors, capacitors, and inductors). If you were to measure all the voltage sources and voltage drops around a loop, their total would ultimately balance to zero, reinforcing the concept that energy is conserved in electrical systems.

This foundational law is crucial in analyzing and solving circuits, particularly when applying techniques such as mesh analysis. It allows engineers and technicians to precisely calculate voltages and understand how they influence circuit behavior.