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How the area of a wire affects resistance

Extracts from this document...

Introduction

Alex

Middle

How the area of a wire affects  resistance

Planning

Background Physics:

What is resistance?

Electricity is conducted through a conductor. In this case it is the wire. Resistance is the word used to describe the opposition to the flow of current. The more free electrons there are, the better the conduction and the lower the resistance is. For example gold is a better conductor then aluminium, therefore it is a better conductor . The more atoms vibrate, the more resistance there is. The free electrons are given energy, as a result they move and collide with the surrounding electrons. This happen throughout the whole wire. This happens because electricity is passing through the wire This is how the electricity is conducted. Resistance is the result of energy loss in the form of heat. If the cross-sectional area doubles, the resistance halves. Resistance is caused by electrons bumping into ions. If the length of the wire is doubled, the electrons bump into twice as many ions so there will be twice as much resistance. If the cross sectional area doubles, there will be double the amount of ions bumping into electrons into each other.

Conclusion

 X Y 1 1 2 0.5 3 0.333 4 0.25

To test this I have plotted an average 1/Area. If it is correct then I should  get a straight line. When I plotted the graph I had a straight line.

This tells me that the average is proportional to 1/Area i.e. Rave α 1/Area.

The slope is: y/x= 10.5/16= 0.66 Ω m²

I am ignoring the offset on my 1/Area graph

This experiment shows me that resistance is definitely affected by the area of the wire. Looking at my background physics it has worked out like resistors on a parallel circuit. When attaching another wire to the experiment it acts like adding another  parallel resistor in a parallel circuit.  So if the area of the wire increases the resistance decreases. Also I have learned if the voltage goes down the resistance goes up. This shown by the two graphs  I have plotted.

Evaluation

I found this experiment easy to do. I had no anomalies on my graph. This means that the points I have plotted are all in a acceptable arrangement. There were no experimental caused by a faulty connection. There were no safety hazards and the experiment was safe to do.

This student written piece of work is one of many that can be found in our GCSE Electricity and Magnetism section.

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