NCEA Level 3 Electricity Practice Test 2025 - Free Electricity Practice Questions and Study Guide

Ohm's Law is a fundamental principle in electricity that defines the relationship between voltage (V), current (I), and resistance (R) in an electric circuit. The correct representation of Ohm's Law is expressed as V = I * R. This means that the voltage across a conductor is directly proportional to the current flowing through it, with the resistance being the constant of proportionality.

In this equation, if you know the current flowing through a circuit and the resistance, you can calculate the voltage. For example, if you have a resistor with a resistance of 2 ohms and a current of 3 amps flowing through it, you can find the voltage as follows: V = 3 A * 2 Ω, which equals 6 volts.

This relationship is crucial when designing and analyzing electrical circuits because it helps to determine how much voltage is needed to drive a given current through a specific resistance. Understanding Ohm's Law is essential for anyone working with electrical systems, as it allows for the calculation and prediction of circuit behaviors.