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

Resistance of Wires.

Extracts from this document...


Physics Sc1 Investigation:                                                      Fay Woodhall 11DGB

                                                                                                             Lymm High School

                                                                                                             Center No. 40109

Resistance of Wires.


Re·sis·tance (rimage00.png-zimage00.pngsimage01.pngtimage02.pngns)

  1. The capacity of an organism to defend itself against a disease.
  2. The capacity of an organism, a tissue, or a cell to withstand the effects of a harmful physical or environmental agent.
  3. The opposition of a body or substance to current passing through it, resulting in a change of electrical energy into heat or another form of energy.
  4. In psychoanalysis, a process in which the ego opposes the conscious recall of repressed unpleasant experiences.

I am investigating resistance in the form of the opposition to electric current. I am going to investigate one of the factors that affect the resistance of a metal wire.

Key Factors

  • Diameter of a wire. A wider wire means there will be an increase in the number of positive ions across the cross section; therefore there will be more collisions for the negative free electrons and more resistance.
  • Temperature of the wire. An increase in temperature means the ions in the wire gain energy and vibrate more in their fixed positions, making it more difficult for the free electrons to move past, and increasing the resistance.
  • Length of wire. The longer the length of the wire the more ions the free electrons have to collide with as they move along the wire.
  • Material of wire. Some materials contain ions that are packed very tightly together, where as other materials contain larger spaces in-between its ions. The larger spaces let the electrons move through more easily.
...read more.


100 cm





32 SWG

50 cm




For my preliminary work I will not be using any length of copper wire because its resistance is to low to be measured precisely and it is too like the wires used within the circuit. I have also decided not to use 24 SWG constantan because the resistance is too low to be measured accurately, unless I use the longer lengths. The longer length would cause problems in accuracy because the wire twists, making it difficult to measure the length accurately. The 32 SWG constantan would be good to use for my investigation because it has a good range of resistances within a length of 1m and they are large enough to be measured with precision. I will use lengths of 25 cm, 40 cm, 55 cm, 70 cm, 85 cm and 100 cm. I will use this range of 5cm steps because I think that it will give better-spaced results. I am not going to use lengths lower than 25 cm the resistance would be too low to measure accurately and I will not use lengths longer than 100 cm because the twists in difficulty in handling could cause problems in accuracy when measuring the lengths against the metre rule.

Main Investigation


The apparatus will be set up as shown in the diagram.

...read more.


Comment on Method

My method has proved suitable but it could be improved. I could have also controlled the temperature better by using smaller current. However this would require a more sensitive Voltmeter and Ammeter to ensure precise readings. I would need a meter that read to 0.001A and 0.001V. Another way of improving my method is by ensuring the wire had a constant diameter along the whole length of the wire. I could do this by checking at various points of the wire with a micrometer that measures to 0.01 mm. In order to ensure the correct lengths of wire were maintained throughout the experiment I could have used smaller crocodile clips that would have a much tighter hold on the wire to prevent any slipping altering the measured length.

Additional Work

In order to obtain extra evidence and support and further my conclusion I could measure the resistance of smaller lengths of 32 SWG constantan wire. However this would require a different technique in which I would have to measure the resistance directly, using a multimeter set on the Ohms scale. Alternatively I could measure the resistance of small lengths by adopting the circuit used previously. I could use a variable resistor in order to enable finer control of the current. This method would require more sensitive ammeters and voltmeters, as the readings would be smaller.

...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. Peer reviewed

    Investigation in resistance in wires

    5 star(s)

    should raise the length of the wire, lower the voltage and raise the controlled resistance, as I mentioned earlier, the reason for a wire temperature rising is that when a current passes through a wire collisions occur between the electrons and the ions and when collisions occur the electrons lose

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

    We used a power pack instead of batteries because power packs will supply continuous electricity and we can change the voltage. Batteries run out of electricity and only supply a certain amount of electricity. Justified prediction I predict that the longer the wire the higher the resistance because the resistance

  1. Finding a material's specific heat capacity

    Due to the insulation, the copper will be much hotter to the touch than the outside of the flask and allowances must be made for this. The ammeter and voltmeter must always be set to the correct settings before they are turned on so as to avoid dangerously fusing them due to current surges.

  2. Resistance and Wires

    These results support the claim that the results are very accurate. There is also a definite trend or pattern which the results follow. This also supports the fact that the data is accurate because it there are no stray results and each reading fits nicely into a pattern when drawn on the graph.

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

    * I will not use lengths of wire, which are lower than 10cm, because current rises if shorter lengths of wire are used. Using longer lengths of wire will help to reduce currents and therefore reduce the wire from getting too hot.

  2. Resistance of wires

    Safety and Experimenting Fairly Safety ~ Safety is an important issue as we are working with high voltage equipment. We must be aware of risks and the danger of electrocution. To evade the hazard of electrocution, we must first turn down the electricity knob on the energy supply pack to

  1. Aseptic technique

    The neck of the bottle was then placed into the centre of the combustion flame and neck of the bottle was 'flamed'. As the loop was very hot I was held to cool for a few second before being inserted in to yeast bottle to pick up a film of yeast culture.

  2. Resistance of Wires

    and 0.91 mm (20 swg - the thickest wire). I varied these wire lengths to obtain two sets of results from each wire: 29 cm (the largest length) and 5 cm (the shortest length). These two extremes in wire thickness made sure that I could make a decision on what

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