Resistance of a Wire Experiment

Resistance of a Wire Experiment

There are a range of factors that can affect the rate of resistance in

a wire.

These include:

· Length of wire

· Thickness of wire

· Temperature

· Material

For my investigation I have chosen the first factor, the length of

wire. I will see how the length affects the resistance.

Resistance is the property of an electrical conductor, to work against

the flow of the current and change some of the electrical energy into

heat. The quantity of resistance in an electric circuit determines the

amount of current flowing in the circuit for any given voltage applied

to the circuit, according to Ohm's law. The unit of resistance is the

ohm and the amount of resistance that limits the passage of current to

one ampere when a voltage of one volt is applied to it happens. The

standard abbreviation for electric resistance is R and the symbol for

ohms in electric circuits is the Greek letter omega, Ω.

Formula:

Resistance = potential difference / current

= V/I

So therefore in order to find the resistance I will need to find the

potential difference and the current in the circuit.

Now I will explain the potential difference briefly. It is the

potential difference that pushes electrons around the circuit. So if

the wire has more electrons then there will be less current thus a

higher resistance eg. 6 volts / 3 amps = 2 ohms resistance. Therefore

if there was 6 volts but 2 amps, the resistance would be 3 ohms.

To start with I am going to carry out some preliminary work in order

to find out the best apparatus to use and decide on what the

increments will be.

Preliminary Method:

· First of all one must consider the safety issues in this experiment,

integral to any investigation. The wire is likely to get very hot so I

must not handle it.

· Now here is the equipment needed for this experiment: