• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month
Page
  1. 1
    1
  2. 2
    2
  3. 3
    3
  4. 4
    4
  5. 5
    5
  6. 6
    6
  7. 7
    7
  8. 8
    8
  9. 9
    9

Determine how the effect of electrical resistance changes with varied length of a metal wire.

Extracts from this document...

Introduction

Electrical Resistance Coursework

Aim

This coursework is based on the topic of electrical resistance.  The aim of this coursework is to determine how the effect of electrical resistance changes with varied length of a metal wire, which is the factor I will be investigating.  In order to do this, I will measure the resistance of the wire at equal length intervals, using a voltmeter in parallel and ammeter in series, and then record the change in resistance in relation to the length of the wire.  In the end I am going to find out as to how resistance of a metal wire varies in relation to the length of the wire used.  

Theoretical Background

        Firstly, resistance shall be dealt with.  Electrical resistance is the opposition to the flow of electric charge (current).  With a given energy source, such as a battery, the size of the current that flows is determined by the resistance of the circuit.  All conductors resist the flow of electric charge to a certain extent, but some conductors are better resistors than others.  The bigger the resistance of a conductor, the harder it is for electric charge to flow through it.

        With a conductor of high resistance, the amount of charge flowing through it is reduced, and energy is released, resulting in the conductor becoming hot, due to friction.

        Resistance can be defines as the ratio of the voltage across an object to the current flowing through it.  The formula to work out the resistance is:

...read more.

Middle

increase in resistance, due to frequent collisions.

To do this I would use the same length and width of many different wire materials, using the same amount of voltage each time.

Finally, the length of the wire is a factor. The longer the wire, the longer it will take electrons to get to the end of the wire. This is because there will be more collisions between electrons and atoms. So, in theory, the length of the wire should be directly proportional to the resistance.

This would be very easy to do, and give accurate results. Because of the length being proportional to the resistance, I could link the length of a wire with the resistance of the wire, which would make my graph more interesting.

Due to the effectiveness of this method, I have decided to use the length of the wire as the factor that I am going to use.

Prediction

I predict that, the longer the wire is, the more resistance there will be due to more collisions between the electrons and atoms. The length of the wire should be approximately proportionally the same as the resistance. In theory, if the wire is doubled, then so will the resistance. If the length is twice as much, then there will be twice as much collisions, which would increase the resistance.

Method

Apparatus

· Crocodile clips

· Ammeter

· Voltmeter

· Power supply

· Meter ruler

· Connecting wires

· sticky tape

· Thin Constantine wire

Diagram

...read more.

Conclusion

As you can see in the diagram, the wire on the top is twice as big as the one below it, so it has twice the electrons too.

Evaluation

This experiment has gone satisfactory, but there have been certain things in the experiment that I have not been pleased with.

Some of my results have turned out anomalous. This mainly being:

60cm Anomalous

V

I

R

1

0.09

11.11

1.5

0.13

11.54

2

0.18

11.11

2.5

0.21

11.91

3

0.25

12.00

3.5

0.29

12.07

4

0.33

12.12

I have probably ended up with this anomalous result because of an error in recording my results.

However, as you can see from my average resistance graph, the results are roughly on the same line, so this anomalous result did not do much harm when the results are averaged.

I have noticed, now that I have finished my coursework, that there are a number of things I could have done to get more accurate results.

Firstly, I would do the experiment using the width and the material used as a factor too, just to make sure that my averages are as correct as possible.

The next thing I would have done is to use pointers instead of the crocodile clips which I used. This is because pointers are a lot more accurate, because they have a smaller surface area on their tips than crocodile clips. This in effect would give much more accurate measurements.

...read more.

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

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related GCSE Electricity and Magnetism essays

  1. The Efficiency of an Electric Motor.

    I made many assumptions when I was calculating R. For example, I assumed that V and R are constant. I also assumed that ? was constant through out my experiment, when it actually decreased as the radius of the motor shaft increased. As a consequence of this the value of the internal resistance is only an estimation.

  2. Investigate one or more factors affecting the resistance of metal wires

    Note that I did not have to measure out the diameter of the wire using the Micrometer screw gauge since it was already done for us. Measurements: * The length of wire (L) between the crocodile clips was measured using the meter ruler.

  1. Investigating The Effect Of Resistance On A Capacitor Circuit

    0.919 33 0 0 0.028 0.233 0.897 33.5 0 0 0.028 0.226 0.876 34 0 0 0.021 0.212 0.862 34.5 0 0 0.021 0.205 0.841 35 0 0 0.021 0.198 0.82 35.5 0 0 0.021 0.191 0.806 36 0 0 0.014 0.184 0.791 36.5 0 0 0.014 0.177 0.77 37

  2. How does length and width affect resistance

    A low voltage of 6V was chosen so that overheating was minimised, but the experiment remained its original speed. Furthermore, lengths lower than 10cm were not tried, which also helped to avoid overheating. Fair testing It is important that when I do the experiment, I make it a fair test in order for it to produce accurate and reliable results.

  1. To investigate how the electrical resistance of a wire changes in relationship to its ...

    My results prove this. There is however one hugely anomalous result which I will try to explain in the next section. From these graphs, to sum up: * The graph of average resistance versus length of wire, it can be seen that the two are directly proportional as it is a straight line, which passes through the origin.

  2. Resistance Coursework

    This is because the electrons collide with the material of the nichrome wire. Then I clip two crocodile clips, one on each side of the nichrome wire and then connect in the voltmeter and ammeter using wires which I plugged into the power pack/supply which has plugged into the mains.

  1. To investigate the factors which effect the resistance of a metal wire.

    Thirdly, the material used would be a factor. If the material being used contains atoms with a large number of electrons on the outer shells, then this means there are more electrons available. So, in theory, if the material has a large number of atoms, there should be less resistance,

  2. Does the length of a wire effect the Resistance?

    Whereas in a shorter wire the electrons don't pass as many atoms therefore they experience a resistance which is lower. This again can be compared to a corridor. It will take longer to get the whole way down the corridor rather than half way, if the conditions are the same.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work