Investigating How Different Lengths of Wire Affect the Resistance in a Circuit

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Investigating How Different Lengths of Wire Affect the Resistance in a Circuit

Hypothesis: I predict that; the longer the wire, the more resistance

there will be. So if the length of the wire were to double, so would

the resistance. The reason for my prediction is: The flow of electrons

is called a current, the electrons are constantly hitting atoms, which

causes resistance. If the same amount of current is passed through a

longer piece of wire, there will be more collisions, hence more

resistance.

The more resistance there is, the more volts would be needed to push

the current around the circuit, so the longer the wire, the higher the

current. I can check the voltage, current and resistance to prove that

my hypothesis is correct by using ohms law which is V=I*R (V=volts,

I=amps and R = resistance). I can re-arrange this formula to find the

resistance by saying R=V/I, so when I record my results, I should

divide the volts by the current to give me the resistance. The voltage

and the resistance are directly proportional.

Equipment:

A voltammeter.

An ammeter.

A thin piece of wire attached to a wooden ruler.

Connecting wires with crocodile clips.

A power pack.

Method:

Step 1: I will set up a circuit with a power pack, a voltammeter, and

an ammeter.

Step 2: I will attach a piece of thin wire to a meter long ruler.

Step 3: I will have one plastic coated wire fixed to where the thin

wire is at 0cm on the meter stick.

Step 4: I will then crocodile clip the other plastic coated wire to my

first chosen length on the thin wire which is attached to the meter

stick.

Step 5: I will record the length, the reading on the voltammeter and

the reading on the ammeter, and then work out the resistance, using

ohms law (dividing the volts by the amps).

Step 6: I will then repeat this using different lengths each time, and

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