Key Stage 3 (KS3) Physics Practice Test

Ohm's Law states that the voltage across a conductor is directly proportional to the current flowing through it, provided the temperature remains constant. This relationship can be expressed mathematically as Voltage = Current × Resistance. In this context, "voltage" refers to the electric potential difference, "current" refers to the flow of electric charge, and "resistance" is a measure of how much the conductor opposes the flow of current. This fundamental principle forms the basis for understanding electrical circuits and is essential for calculating how components in a circuit relate to each other. Understanding this law is critical for analyzing circuits; it allows students to determine how changing one variable (like current or resistance) will affect the others (like voltage). The other options do not accurately represent Ohm's Law: the power equation relates power to voltage and current but does not reflect the relationship of Ohm's Law, and both energy and resistance equations presented do not represent the direct relationship defined by Ohm's Law.