• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Investigation into how the length of a piece of wire effects its resistance

Extracts from this document...

Introduction

Investigation into how the length of a piece of wire effects its resistance

Aim

Using different lengths of constantan wire, investigate how different lengths of wire effect its resistance.

Planning

My preliminary work before the actual experiment included going on a Science computer programme, on the topic resistance of a wire. In which I used to decide upon how I was going to do my experiment. I will take readings of lengths of wire from 0-70 cm and to make these readings accurate I will do them three times and take an average.

This is what the circuit will look like:

Prediction

I predict that the longer the length of the piece of wire, the more resistance it has. So, if you double the length of the wire, the resistance would be doubled aswell. When a metal wire is put into an electrical circuit, current from the battery makes the electrons flow through the wire. In doing so, they collide with the metal ions and this slows down the flow of electrons in the circuit. So, in a longer piece of wire you would expect more metal ions, with more metal ions there you would expect there to be more electrons colliding with them. Resistance is caused by electrons colliding

...read more.

Middle

2.9

2.7

70.0

3.4

3.5

3.4

3.4

3.2

Conclusion

The graph and results show me that the longer the wire, the more resistance it has which supports my prediction. In a longer piece of wire there would be more metal ions, and so more metal ions for electrons to collide with slowing their progress thus increasing resistance of the wire (resistance is a measure of how easy it is for the electrons to flow through the metal). Effectively, if you doubled the length of wire you would be doubling the resistance too. My results generally show this, but not as accurately. An example of the resistance being doubled when the length is doubled is when the length of wire was at 10.0 cm, the resistance of the wire was 0.5 Ohms. 10.0 cm doubled is 20.0 cm, and at 20.0 cm the resistance was 1.3 Ohms. 0.5 doubled is 1. It’s relatively accurate but not double exactly. I expected in my prediction that if you doubled the length of wire you would then double the resistance as it makes sense that if the wire were twice as long, the electrons would undergo twice as many collisions. If it’s twice as difficult to travel along the wire, we say that the longer wire has twice the resistance. My graph generally shows that length is proportional to the resistance, although it doesn’t clearly show this.

Evaluation

Overall, I think the experiment was done reasonably accurately.

...read more.

Conclusion

Evaluation

I found that I got much more accurate results in experiment 2 than I did in the first experiment. They were more reliable to make my overall conclusion. The results did prove my prediction. Although they aren’t completely accurate, as I think there is always some inaccuracy or error in results. In the second experiment a current was put through the wire, and this causes the temperature to rise, which will cause ions in the wire to vibrate, and so obstruct the flow of electrons, effectively causes the resistance to increase creating an error. However, when I was doing the experiment when taking the readings I turned the power pack off, so the temperature wouldn’t get to high.

        There are other limiting factors which could have affected my results which I have mentioned, like inaccurate meter ruler readings, temperature change or a unique error etc. But also when I used the variable resistor to keep the ammeter reading constant, it wasn’t always exactly the same as I couldn’t always get it to be the same reading every time.

        If I could do this experiment again I would use other variables aswell like temperature. How temperature might have an effect is that it provides metal ions with more kinetic energy, causing them to vibrate more, thus causing more electrons to collide with them. This causes the resistance to increase.

...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. An in Investigation into the Resistance of a Wire.

    Resistance/ohms Average Resistance/ohms 100 0.32 0.07 4.57 4.57 (4.6) 0.37 0.08 4.63 0.45 0.10 4.50 0.65 0.12 4.64 1.22 0.27 4.52 90 0.33 0.08 4.13 4.12 (4.1) 0.41 0.10 4.10 0.62 0.15 4.13 1.07 0.26 4.12 2.02 0.49 4.12 80 0.30 0.08 3.75 3.72 (3.7) 0.37 0.10 3.70 0.52 0.14 3.71 0.89 0.24 3.71 1.19 0.32 3.72 70 0.26 0.08 3.25 3.23 (3.2)

  2. Free essay

    Resistance Investigation. My aim in this investigation is to measure the amount of resistance ...

    be able to cross all the points through the error bars and it did. In terms of quantitative relationships between the variables and the results for resistance values, approximately as the length of the wire is doubled, the resistance is also doubled.

  1. Resistance of a Wire Investigation

    Material Of these the variables will be input and output voltages in experiment one, and length and resistance in experiment two. The other variables (temperature, material and voltage) will have to be kept constant in both experiments to make sure that only length, thickness, and resistance are investigated.

  2. The resistance of wire.

    wwef efw esefefs ayef efba nef kcef efuk. Apparatus -Power Supply, Ammeter,Voltmeter,Just over 100cm of E26 Wire,Meter Rule,Two Crocodile Clips,Connecting Wires. Factors which must stay constant to keep the experiment a fair test The power supply must stay on 4V, The wire must be the same thickness, The surrounding temperature must be constant, The equipment should be kept

  1. Resistance in a Wire Investigation

    independent variable is the length of the wire and the dependant variable is the resistance. The factors that I will keep the same during this experiment are : "h The temperature "h The thickness of the wire "h The type of wire Safety Precautions : There are not many safety

  2. p5 investigation cwk- resistance of a lightbulb

    Also I decided to use another smaller bulb with a decreased wattage to ensure that the conclusions that I had made are correct. For this experiment I completed the investigation with a 5W and 24W Filament Bulb, recording the voltage and current at particular intervals.

  1. Why Is There More Resistance In A Longer Piece Of Wire?

    The graph that I will plot should be a straight-line graph; according to Ohm's law. Ohm's law states that for most conductors, the current flowing is proportional to the voltage, provided that the temperature does not change. For example, if you double your length of wire, then the resistance will also double.

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

    The units of volts are equal to joules per coulomb. So ohms law tells us that the more resistance means that there is more energy used up to whilst passing through the wire. Resistance is a measure of how much energy needed to push a current through something.

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