What is Kirchhoff’s Voltage Law?

• A. The current in a circuit is constant
• B. The sum of the electrical potential differences around a closed loop is zero
• C. Voltage across parallel components is the same
• D. Resistance in series circuits is cumulative

Answer: (B)

Kirchhoff's Voltage Law (KVL) states that the sum of the electrical potential differences (voltages) around any closed loop in a circuit must equal zero. This law is based on the principle of conservation of energy, which implies that the energy supplied by sources in the loop must be equal to the energy consumed by resistive elements within that loop. When tracing a complete path through the circuit, any rise in voltage (such as across a battery) will be balanced by a drop in voltage (such as across resistors). This relationship helps in analyzing and solving electrical circuits by allowing engineers and technicians to set up equations that represent the different voltages in the loop to find unknown values.

Understanding this principle is crucial for working with both simple and complex circuits, as it helps to ensure that energy is accounted for throughout the system.