Resistance of a Wire - Practical Experiment
How does the length of a wire affect how much it resists electrical flow? This experiment helps us find out! You'll attach a wire to a metre ruler with tape and connect it in a circuit using crocodile clips. This setup allows you to measure different lengths of the same wire.
Start by positioning your crocodile clips 10cm apart on the wire. Measure and record both the current and voltage at this point. You'll calculate the resistance using the formula R = V/I (resistance equals voltage divided by current). Then repeat these measurements at 5cm or 10cm intervals along the wire's length.
💡 Always turn off the power supply between readings! This prevents your components from heating up, which would affect your results as temperature changes resistance.
When you plot your results on a graph (resistance against length), you'll discover that resistance is directly proportional to the length of wire. This means that doubling the length doubles the resistance! In this experiment, you need to control variables like temperature, wire thickness, and wire material to ensure fair testing.