NCEA Level 2 Electricity Practice Exam

Kirchhoff's Voltage Law (KVL) is a fundamental principle in electrical engineering that provides insight into how voltage behaves in closed circuits. The law states that the sum of all the electrical potential differences (or voltage changes) around any closed loop in a circuit must equal zero. This is due to the principle of energy conservation; as electric charge moves around the loop, the energy supplied by the voltage sources is completely used up by the resistive components within the circuit, leading to no net change in energy. In this context, if you were to measure the voltages across each element in the circuit and sum them up—taking into account the polarity of each voltage drop and source—the result would be zero, effectively indicating that energy is conserved in the loop. This is a foundational concept that underpins circuit analysis, ensuring that all relationships between voltages are in balance within closed circuits. As such, the correct choice accurately reflects this law and its implications for electrical circuits.