The Resistance of a Wire Investigation

The Resistance of a Wire Investigation

Aim: To investigate how changing the length of a wire affects the

resistance.

Prediction: I predict that the longer the piece of wire, the greater

the resistance will be. This is because the current is resisted by the

atoms in the wire. In a longer piece of wire, there would be more

atoms for the electrons to collide with and so the resistance would be

greater. The shorter piece of wire will have less resistance because

their will be less particles causing less collision.

I also predict that the length of the wire and the resistance will be

directly proportional.

Plan: In this investigation a simple circuit will be set up to read

the voltage and current when the length of the wire changes. The

length will range from 10cm - 100cm with intervals of 10cm. The length

of the wire will be changed by moving the crocodile clip across the

wire on a ruler.

We did preliminary tests to ensure that the wire did not get too hot,

If the wire got too hot, energy would be given off as heat.

The circuit should be set up as in the circuit diagram. It is

important that the voltmeter is set up in parallel and the ammeter in

series. The readings from the ammeter and voltmeter will be used to

work out the resistance.

Hypothesis: many different things can effect the resistance of a wire.

Diameter: A small diameter will have a small surface area creating

more resistance. A large diameter will allow the current to pass more

freely with less resistance.

Length: The of the wire will also affect the resistance. If the wire

is long their will be a higher resistance because their will be more

particles for the current to pass.

Fair Test: To ensure that the investigation is carried out in a fair

way and that the results will be accurate and reliable a number of

things must be followed. The only variable in the test will be the