Factors which affect the Resistance of wires

* Resistance is measured in ohms.

* A resistor has the resistance of one ohm if one volt is necessary to push a current of one amp through it.

* Resistance occurs when the electrons travelling along the wire collide with the atoms of the wire. These collisions slow down the flow of electrons causing resistance. Resistance is a measure of how hard it is to move the electrons through the wire.

* Ohm's Law states that Resistance = Voltage over Current (R=V/I)

Consequently my prediction would be that; with the wire's length increasing the resistance will also increase, because the electrons will have a longer distance to travel and so more collisions will occur. Due to this, the length increase should be directly proportional to the resistance increase.

To measure and record the results for this the results will be collected on a table.

Length ( cm )

Volts ( V )

Current ( Amps (I) )

Resistance ( V/A )

0

20

30

Etc...

Equipment

Three 9V cells,

Ammeter,

Voltmeter,

A spool of 22 SWG, Nichrome Wire,

Meter Rule,

Two Crocodile Clips,

Connecting Wires,

Wire Cutters.

My method for carrying out the experiment is as follows; firstly the circuit will be set up as shown below.

Then I will cut some lengths of wire, measuring them with a metre ruler. The power supply will be 3 cells of 9V. I have decided to do the lengths probably up to 100 centimetres inclusive and will continue to go up in 10 centimetre intervals.

The only things that I'll be measuring will be; the length of wire, the voltage, and the current. To make this experiment a fair test the only thing that I'll be changing will be the wire length: The wire type (Nichrome), temperature, and diameter (22SWG) will be kept roughly the same. I will also keep the voltmeter, ammeter, and the cells the same.

I will have to be careful when touching the wire, as it may be hot because the resisted energy will probably be turned into heat energy.

A graph will be displayed to show the, hopeful, connection between the length of the wire and the resistance given by the wire. I will use the 10 points to mark on a graph, to see if my predicted result works, this will show in a certain pattern.