Resistance of a Wire

Resistance of a Wire

We are trying to find out what affects the resistance of a wire.

Resistance is the slowing down of electric flow (flow of electrons)

due to metal ions. The equation to measure resistance is:

Resistance = Voltage ÷ Current

R = V / I

Resistance is measures in 'volts per amps' or, more commonly, 'Ohms'

(Ω).

There are a few things that affect resistance. I think these are:

¶ Length of wire

¶ Diameter of wire

¶ Material/type of wire

¶ Temperature

I am going to try and find out how the diameter of the wire affects

the resistance of the wire. I will do some tests find out how the

diameter affects the resistance. I think that if I increase the

diameter the resistance will decrease.

Method

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1. First I will set up a circuit with a power pack, voltmeter, ammeter

and a space for a 1metre wire.

2. Then I will get a metre ruler and measure 1 metre of the first size

of wire and cut it with wire cutters.

3. I will stick the wire to the metre ruler with two pieces of sticky

tape 2cm away from either end to keep the wire straight.

4. I will then put the wire (attached to the ruler) in the gap in the

circuit and attach it to the circuit.

5. After turning the power pack on, I will record the numbers on the

voltmeter and ammeter.

6. I will then repeat steps 2 to 5 with 4 other different Standard

Wire Gauge sizes of wires.

7. Next I will repeat the whole experiment another few times.

I have chosen this method because it is quick, practical and easy to

do and will produce accurate and reliable results. I think it is the

best because it is the easiest one to do and you don't need that much

equipment but still get good results.

Apparatus

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