What is the purpose of an I-V characteristic experiment?

The purpose of an I-V characteristic experiment is to investigate the relationship between current and voltage in a component.

In an I-V characteristic experiment, you measure how the current (I) flowing through a component changes as you vary the voltage (V) across it. This relationship is crucial for understanding how different electrical components behave in a circuit. For example, resistors, diodes, and filament lamps each have unique I-V characteristics that can tell you a lot about their properties and how they will perform in various electrical circuits.

For a resistor, the I-V characteristic is typically a straight line, indicating that the current is directly proportional to the voltage. This linear relationship is described by Ohm's Law, which states that V = IR, where R is the resistance. By plotting the current against the voltage, you can determine the resistance of the resistor from the slope of the line.

In contrast, a diode has a non-linear I-V characteristic. A diode only allows current to flow in one direction, and it requires a certain threshold voltage before it starts conducting. Below this threshold, the current is almost zero, but once the threshold is surpassed, the current increases rapidly with a small increase in voltage. This behaviour is essential for components used in rectifying circuits, which convert alternating current (AC) to direct current (DC).

Filament lamps also exhibit a non-linear I-V characteristic. As the voltage increases, the filament heats up, causing its resistance to increase. This results in a curve where the current increases at a decreasing rate as the voltage rises. Understanding this behaviour is important for designing circuits that involve lighting.

By conducting an I-V characteristic experiment, you can analyse these relationships and gain insights into the electrical properties of various components, which is fundamental for designing and troubleshooting electronic circuits.