NCEA Level 2 Electricity Practice Exam

Kirchhoff's voltage law states that the total voltage around a closed loop in a circuit must equal zero. This principle is grounded in the conservation of energy, indicating that the energy supplied by sources (like batteries) will be completely consumed by the resistive elements (like resistors) and any other components in the loop. Essentially, as you navigate around the loop from one point to the same point again, any voltage gained from a source must be balanced by the voltage drops across the components, resulting in a net voltage of zero.

In other words, if you were to quantify the voltages in a closed circuit loop, any rise in voltage from a power supply must be exactly countered by the voltage drops across other components like resistors or loads, affirming that no energy is created or destroyed within the loop. This ensures that every unit of electrical energy used is accounted for, reinforcing the foundational principles of circuit theory.