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

Factors affecting the resistance of a wire.

Extracts from this document...


Hannah Marchant


Factors affecting the resistance of a wire


Resistance is a force, which opposes the flow of an electric current around a circuit so that energy is required to push the charged particles around the circuit. The circuit itself can resist the flow of particles if the wires are either very thin or very long. E.g., The filament across an electric bulb is quite thin as it needs to resist the flow of particles for the bulb to glow.

Resistance is measured in ohms. George Ohm discovered that the electromotive force of a circuit is directly proportional to the current flowing through the circuit. This means that if you triple one, you triple the other. He also discovered that a circuit sometimes resists the flow of electricity. He called this resistance. He then came up with a rule for working out the resistance of a circuit :

V/I = R

V - Volts

I - Current

R - Resistance.

Plan: Three external factors influence the resistance in a conductor. Thickness (cross sectional area of the wire), length, and temperature all have some effect on the amount of resistance created in a conductor. The fourth factor is the conductivity of the material we are using. Some metals are just more electrically conductive than others are. This however, is considered an internal factor rather than an external one.

For the

...read more.


 we will observe the reading on the voltmeter change as we change the current to 0.25 A. We also observe a general increase in the voltage, as the length of wire we use gets longer. The rheostat will also be set at different positions for the different lengths of wire that we use.

Evidence: to make sure our overall values are as accurate as possible we will repeat our readings and then take the mean resistance. We will also be able to spot and discard any anomalies from our results.  


Set of results 1


(V) Volts

(   ) Amps

























...read more.


I do not think that doing any more results in our experiment would have made it any more accurate.

        During my experiment, I have noticed several modifications I could make to improve on the Investigation if I was to repeat it. I could use pointers instead of crocodile clips; I would do this because pointers would be more accurate. The pointers would be more accurate because the tips have a much smaller area than the crocodile clips giving a more accurate measurement of the length of wire. Perhaps where we to have a bar that didn't bend in place of the wire, it could have been more accurate.

As well as making these modifications, I would also improve my Investigation by testing the same wire but with different widths of that wire. I would do this to expand on my Investigation. I could also try to work out the resistivity of the wire, we could do this by using the formula (                  ) and then work out the percentage of error in our results.

This document was downloaded from Coursework.Info - The UK's Coursework Database

Click here to visit Coursework.Info/

...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 experiment to find the resistivity of nichrome

    2.6 4.8 7.6 10.0 12.8 From these results I have drawn a graph of the length of the wire and the resistance of the wire. Analysis From the graph on the previous page I can see that the resistance of the wire is proportional to the length of the wire.

  2. Resistance of a Wire Investigation

    From both graphs there is a best-fit curved line. This means that the rate of photosynthesis increases at an exponential rate. However, my prediction that light intensity is inversely proportional to the distance squared did not fit into my results perfectly.

  1. Physics GCSE Coursework:Factors affecting the resistance of a wire

    Hypothesis: Electrons bumping into ions on the conductor's atoms cause resistance. If the length of the wire is doubled, the electrons bump into twice as many ions so there will be twice as much resistance.

  2. Discover the factors affecting resistance in a conductor.

    We can use this formula to make calculations with all values for V for a given conductor. However, the resistance may change is the conductor heats up. Many laws in physics are stated to be unbreakable, however this is not how Ohms Law is defined.

  1. Factors Affecting the Efficiency of a Wind Turbine

    This is what I was expecting. Limitations There is in fact a theoretical maximum so there are limitations. The largest fraction of the delivered energy that any of the machines open to winds can extract is equal to 16/27 ths, or just under 60% (according to the book-advanced physics)

  2. To investigate the factors affecting current in a wire.

    But instead I chose to investigate the length because it is easier to do practically and is therefore more accurate and reliable. However, there is a formula to work out the resistance of a wire and it includes the cross-sectional area, length and resistivity of the wire: Fair Test In

  1. Finding a material's specific heat capacity

    The inaccuracy of the temperature probes was only discovered after the experiments had been carried out and could have contributed to any errors in the results. However, as the data value being measured was temperature change, assuming the temperature offset was fairly constant over a large range, this should not

  2. A Visit to Ashford Hospital

    This filament forms the negative cathode. These electrons are accelerated across an evacuated X-ray tube towards the positive anode by a large voltage that is applied across the tube. These electrons strike the anode where 99 % of their energy is converted to heat with less than 1 % resulting in X-radiation.

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