• 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
  10. 10
    10
  11. 11
    11
  12. 12
    12
  13. 13
    13
  14. 14
    14
  15. 15
    15

An experiment to investigate the effects of different lengths of wire on resistance

Extracts from this document...

Introduction

Neha Poshakwale

An experiment to investigate the effects of different

 lengths of wire on resistance

Aim

The aim of our experiment is to investigate how increasing the length of a wire affects the resistance in the wire.

Prediction

The collisions between electrons and atoms in a wire cause resistance. Therefore if I double the length of an identical piece of wire then the resistance should double as well. My point is explained in figure 1 by using an example experiment.  

Therefore we realise that resistance is directly proportional to the length of wire, this means that as the length doubles/increases the resistance doubles/increases as well. So I would expect a straight-line graph from my results if they are accurate, like the one shown below in figure 2:

In figure 3 we can see the amount of resistance in a wire:

image20.png

image24.png

image31.png

image00.png

Ohm's law is a mathematical formula that expresses the relationship between the electromotive force, electric current, and resistance in a circuit.  This relationship was discovered by the German physicist George Ohm, and was published in 1827.  When applied to a direct-current circuit, Ohm's law states that the electromotive force (V), measured in volts, equals the current (I) in amperes multiplied by the resistance (R) in ohms: V = IR.

Resistance is calculated by using the equation below.

...read more.

Middle

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

  1. Then we would record our results in a table and work out the amount of average resistance (average voltage/average current).

To ensure that this experiment is going to be a fair test all the variables except for the length of the wire must be kept the same throughout the experiments. Variables that should not altered include:  

  • Temperature
  • Material
  • Cross-sectional area
  • Type of wire
  • The amount of voltage from the Powerpack.

The effect of these variables is explained at the beginning of my coursework.

Precautions/Safety

I would carry out the experiment keeping in mind the following rules:

  • Keep the current at a safe voltage because it could become hot.
  • Keep our stools well tucked under our chairs to avoid accidents.
  • To use appropriate lengths of wire so that it will not start to get hot or burn.
  • To keep the experiment away from the tables edge so it would not fall.
  • Only turn the Powerpack on when everything is in place.
  • When changing the length of wire to turn off the Powerpack.
...read more.

Conclusion

Overall I thought that my experiment was very successful, however if I had more time and money then my experiment would have been more accurate and reliable.    

If I had more time then I would have repeated the experiment several times (for examples, seven times) this would make my results more reliable. Plus, I could take a wider range of lengths (readings) say may be a 100 or 90 reading instead of just 45 (which is how many readings I took). Another thing that I could do was to investigate other variables, which affect resistance (for example temperature, cross-sectional area and material). Also I could take time to read/research published experiments and use other people's results.

If I had more money I would buy more specialist equipment to take reading (to 5 d.p.) this would make my experiment more accurate. I could also perform the experiment in a special lab where I can alter the temperature, to suite my experiment. I could also purchase a laptop, which could take down the readings and draw the graph for me; this also might make my experiment more accurate.

All my suggestions would make my results more reliable and accurate.


Bibliography

Here are the books/websites I referred to in providing evidence and scientific knowledge to support parts of my coursework:

  • Physics 4 U by Keith Johnson p259
  • Complete Physics by Stephen Pople
  • www.homeworkhigh.com
  • www.learn.co.uk
  • www.schoolsnet.co.uk
  • www.yahoo.com

...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. Marked by a teacher

    The factors affecting the resistance of a metalic conductor.

    4 star(s)

    x A [] 0.12 5.49 4.8 0.25 2.86 3 0.39 1.62 1.8 0.65 0.97 0.9 This graph shows that the cross sectional area of the wire is inversely proportional to the resistance of the wire. GRAPH III: * A series circuit as a factor affecting the resistance of a wire:

  2. Marked by a teacher

    Resistance Aim: my main aim is to investigate the factors that affect the resistance ...

    3 star(s)

    The variation of these atoms block the passage of electrons passing through the wire. A slower flow of electrons will therefore lead to less current passing through the wire hence the longer the wire, the longer the electrons have to travel, so they come across more collision.

  1. Discover the factors affecting resistance in a conductor.

    9552.072 6 1.290 0.001290 8.48 6573.43 3 2.350 0.002350 8.43 3587.234 0 0.000 00.00000 0.00 0.000 This table above shows that when the length decreases, the resistance decreases. I hope to see this trend in my main set of results.

  2. Investigate the resistance of different wires and how at different lengths the voltage increases ...

    said to be good insulators, having extremely high resistance to the flow of charge through them. "Conductor" implies that the outer electrons of the atoms are loosely bound and free to move through the material. Most atoms hold on to their electrons tightly and are insulators.

  1. To investigate how the length (mm) and the cross-sectional (mm2) area of a wire ...

    Therefore, different substances can be grouped as conductors or insulators. The most common conductors are metals because they have 'free' electrons. This allows these electrons to carry the electrical energy so that there is no loss of it from interactions between the electrons and the atoms themselves.

  2. The Bouncing Ball Experiment

    at the start of each experiment, and after the ball has bounced. I can then work out how much energy has been lost overall and work out how efficient the ball is. Drop Height (cm): Calculations: GPE at start (J): Bounce Height (cm): Calculations: GPE after bounce (J): 50 50

  1. The aim of this experiment is to investigate how a change in the length ...

    That is because they are all contributing factors to the either increasing or decreasing the resistance, so even if one factor were to fluctuate, the reliability of the results would be placed in jeopardy. That is because it wouldn't be the change in length causing the difference in resistance solely.

  2. To investigate how the length of a wire effects the resistance of it.

    is connected, as it will be hot Be careful when cutting the wire Ensure that the mains to the power supply are switched off when moving from the circuit when it needs to be measured. The apparatus needed for the experiment are listed below: Power supply Voltmeter Ammeter Nichrome wire

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