Cathodic Protection Tester Practice Exam

What law is obeyed in a series electrical circuit?

1. Ohm's Law

2. Kirchhoff Voltage Law

3. Faraday's Law

4. Newton's Law

The correct answer is: Kirchhoff Voltage Law

In a series electrical circuit, the Kirchhoff Voltage Law is fundamental because it accurately describes how voltage behaves in such circuits. This law states that the sum of the electrical voltages around a closed loop is equal to the sum of the voltage drops across all components in that loop. In a series circuit, components are connected end-to-end, meaning that the same current flows through each component. When you sum up the voltage provided by the power source and the voltage drops across each resistor, their totals must equal zero—this is a direct application of the Kirchhoff Voltage Law. While Ohm's Law is essential for understanding the relationship between voltage, current, and resistance, it applies quantitatively to individual components rather than the circuit as a whole, which is where Kirchhoff’s law comes into play. Faraday's Law relates to electromagnetism and the relationship between electricity and magnetism, while Newton's Law pertains to motion and does not apply to electrical circuits. Thus, in the context of series circuits, the Kirchhoff Voltage Law is the most applicable and relevant principle.