Which law relates voltage, current, and resistance in a simple circuit?

• A. Kirchhoff's Law
• B. Ohm's Law
• C. Coulomb's Law
• D. Gauss's Law

Answer: (B)

Ohm's Law relates voltage, current, and resistance in a simple circuit. It is expressed as V = I × R, where voltage (V) is the potential difference provided by the source, current (I) is the rate of electron flow, and resistance (R) is the opposition to that flow. When resistance is constant, increasing the voltage increases the current proportionally, so doubling the voltage doubles the current. Conversely, increasing resistance while holding voltage steady lowers the current, and lowering resistance raises the current. This foundational relationship lets you predict how a circuit behaves as component values change and is essential for sizing resistors and analyzing power. Other laws describe different aspects of electricity: Kirchhoff's Law deals with the sum of currents at a node and the sum of voltages around a loop, Coulomb's Law describes the force between charges, and Gauss's Law relates electric flux to enclosed charge.