NCEA Level 3 Electricity Test 2025 – 400 Free Practice Questions to Pass the Exam

The correct formula that describes the relationship between resistance, voltage, and current is R = V/I. This equation comes from Ohm's Law, which states that the current (I) flowing through a conductor between two points is directly proportional to the voltage (V) across the two points and inversely proportional to the resistance (R) of the conductor. Therefore, if you rearrange the formula that states V = IR, you can derive R = V/I. This means that resistance can be calculated by taking the voltage applied across an object and dividing it by the current that flows through it.

In this context, voltage is measured in volts, current is measured in amps, and resistance is measured in ohms. Understanding this relationship is crucial in electrical circuits, as it allows one to determine how much resistance a circuit has based on the measured voltage and current. This formula is fundamental in analyzing circuits and understanding how they function.

The other choices do not accurately reflect the correct relationships as defined by Ohm's Law or yield incorrect dimensions. For instance, V = IR is indeed part of Ohm's Law but does not answer the question about resistance explicitly. Similarly, I = VR and R = VI do not align with the established relationships within the