Factors Affecting Wire

What factors affect the resistance of a piece of wire?

What I am going to investigate is, what factors affect the resistance of a piece of wire.

To start this experiment I will need the following equipments:

* Power pack

* Ammeter

* Voltmeter

* 1 meter ruler (100cm)

* 110cm of wire

* Crocodile clips

This shows how the equipment will be set up.

A

V

I will measure the Voltage and also Current of the wire. Once I have recorded the results I will repeat recording the results 2 more times at 2 more different voltages to make the experiment fair then I will find the average. I will record the Voltage and the Current of the wire in every 10 meters.

I will record my results in a format of a table like this.

Length (cm) Current (I)(amperes) Voltage (V) (volts) Resistance ® (Ohms)

10m

20m

30m

40m

50m

60m

70m

80m

90m

100m

For the Current and the Voltage there will be 3 results then I will find the Resistance and get the average from that.

To find the Resistance of the wire I will use a pyramid method. The pyramid is shown like this.

V

I R Resistance = Voltage / Current

Once I have done all of that I will then plot a graph showing the results of the experiment.

The graph will look like this it will be a line graph once I have plotted it.

Resistance

Length of the Wire

This diagram shows how the electrons move freely.

Current = moving charge of electrons

My prediction is that the longer the piece of wire is the higher resistance will be. As the length goes up the resistance goes up.

I predict this because the moving electrons in the wire will have to travel twice as much when moving up the wire. They will have to bump in to more atoms the further they go up the wire.

Results

At 3 volts

Length (L) cm Amps (I) (amperes) Voltage (V) (volts) Resistance (R)

(Ohms)

10 2.50 0.16 0.06

20 2.33 0.26 0.11

30 2.21 0.36 0.16

40 2.10 0.44 0.20

50 2.04 0.48 0.23

60 1.93 0.57 0.29

70 1.86 0.61 0.32

...