Mapping How Components Behave with Electricity

⚡ Mapping How Components Behave with Electricity

Every electrical component responds differently when you apply a voltage across it. A resistor at room temperature obediently follows Ohm's Law — double the voltage, double the current. But a filament lamp misbehaves: as it heats up, its resistance increases, so the current grows more slowly. And a diode is even more dramatic — it barely conducts at all in one direction, but conducts freely in the other.

To understand these behaviours, physicists draw I-V characteristic graphs. These plots put voltage (V) on the horizontal axis and current (I) on the vertical axis. The shape of the curve tells you everything about how the component behaves — whether its resistance stays constant, increases, or changes with direction.

This is a Required Practical in GCSE Physics. You build a circuit, vary the voltage using a variable resistor, and measure both current and voltage to plot the characteristic curve for each component.