Find out the resistance of a piece of wire

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Physics Resistance Experiment

Aim- I aim to plan and carry out an experiment to find out the resistance of a piece of wire. I aim going to use Nickel Crome ( 0.71mm). I will record my results in a table and then transfer them to a graph. Whilst doing the experiment we will use a planned out strategy with sensible lengths of the wire. This means that I had to keep some things the same and but to only have one variable/ difference. So as to produce precise and reliable evidence I will make sure that the same person does the measuring /the same person reads the ammeter and voltmeter/ and one person takes the results. To find the resistance of the wire I will use this equation: R=V/I  (V= potential difference, I= current, R= resistance)

Fair testing- (controlled variables) to make sure that it is a fair test;

We will keep these the same-

  • Same ammeter
  • Same voltmeter
  • Same amount of current running through the wire
  • ruler (for measuring the wire)
  • the same person reading the meters
  • same person measuring

And we will change the length of the wire by shortening it 10cm each time. We will draw up graphs and conclusions from our results.

Prediction- I predict that if the length increases then the resistance will also increase. This is because the electrical resistance and current are linked. People change the resistance to manipulate the current flow. This is why i am using the equation V=IR. This is because the longer the wire the more atoms there are to pass through. This means if I triple the length the resistance should also triple. As the current moves along the wire it collide with the atoms, the longer the wire the more collisions. I think that the length will effect the resistance more than the thickness will.

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The electrical resistance is increased because as more current is pushed though the filament it becomes hot and the atoms in the filament ‘jiggle’ about more because they have more energy. While the atoms are ‘jiggling’ more, there is less space for the current to pass through causing the electrical resistance to increase.

All materials are slightly resistant to electricity. Factors affecting the resistance are: Length, Voltage & Temperature and Surface Area.

Length: the longer the wire the more atoms.

Voltage: the more voltage the faster the current flows.
Voltage and temperature: temperature has and affect on the experiment. As the higher the voltage ...

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