What Factors Affect the Resistance of a Wire?

To make it a safe test I will check the circuit before I use it, I will not use the circuit with wet hands, and I wont leave the circuit unattended.

I predict that the resistance will change because I think that the longer the wire the greater the resistance. Also I think that different types of wire will have different resistances.

Below is a list of the equipment I will need for this experiment.

• Power source
• Crocodile clips
• Light bulb
• Ammeter
• Voltmeter
• 2 types of wire
• Jockey
• Variable resistor

DIAGRAM

METHOD

I will set up the circuit as shown in the diagram to see if the resistance in a wire changes when certain variables are changed. First I will draw a table to put my results in. I will record the voltage, type of wire and current. Because I am changing the length of the wire I will have to record the results when the wire is set at different lengths. Then by finding the voltage and current I will use the formula      

R = V

        I          to find the resistance.

RESULTS

1st set

2nd set

AVERAGE OF THE TWO SETS OF RESULTS

1ST set

2nd set

CONCLUSION

I predicted that the resistance would change when the current was flowing through different lengths of wire. My prediction appears to have been correct, the more wire there was the more resistance the wire had.

I also predicted that the resistance would be different for the two types of wires (constantan and nicrome). Again my prediction appears to have been correct the nicrome wire had more resistance than the constantan.

EVALUATION

The experiment was to find ‘ what factors affect the resistance of a wire’. I feel that I’ve proved that length and type of wire are key factors. I also felt that my method was quite successful because I had no problems with the experiment. I think that my results are quite accurate since I did the experiment twice and took an average. I also did a fair and safe test.