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

Resistance in a wire - investigate whether or not the length of a piece of a wire affects the resistance

Extracts from this document...


Physics Coursework


To investigate whether or not the length of a piece of a wire affects the resistance

Background Information

Resistance is a measure of how difficult it is for a current to flow in a circuit. It is measured in Ohms.


The higher the resistance the lower the current.

 Ohm’s Law is all about resistance. It is: I = V/R.

So to work out resistance the equation is R = V/I.


I plan to investigate how the resistance of a 32 swag nichrome wire is affected when i change the length of the wire that is used in the experiment.

Length of Wire (cm)

Current (A)

Voltage (V)



Wire at 10cm





Wire at 20cm





Wire at 30cm





When I did the preliminary I did not use a variable resistor. In order to get accurate results I must keep my current the same at every length. To do this I can use a variable resistor. By adjusting the settings on a resistor

...read more.


Cello-tape                                                x1

Lead – To create the circuit with and to keep it complete in order to carry out the experiment.

Crocodile Clips – To attach the leads to the nichrome wire and allow the circuit to be complete.

Variable Resistor – To control the current and keep it the same at every length in order to make my experiment a fair test.

Nichrome 32 swag wire – This is the wire I am testing the resistance of.

Metre Ruler – This is used to keep the nichrome straight and to measure the length of the wire.

Power Pack – This is my power supply. Without it the circuit would not work.

Ammeter – This is used to measure my current.

Voltmeter – This is used to measure my voltage.

Calculator – I will use this to do the calculations and work out my resistance using Ohm’s Law.

...read more.


I can tell that my results are fairly reliable because, on my graph, my line of best fit falls in between all but one of the error bars. However I cannot be totally sure of my results as two of my results had to be discounted. This was because they were drastically different to the other results in that sample. These outliers could have been caused by a slight error in measuring out the wire or by an error when setting the variable resistor to keep the current constant. This could have caused a fluctuating current. These problems can be resolved by checking everything before I take any readings.        

One thing I could have to done to improve the reliability of my results was to do more repeats. If I had more readings then my averages would become more reliable. However I feel that with the amount of repeats that I took I can be, overall, fairly confident in my results.

...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

    Investigating how the length of wire affects its resistance

    3 star(s)

    In terms of my data collected, looking at my graph, there is an anomaly. I can see this as tall the points are very close to the trend line except for one. When the length of wire was at 50cm, the point is far off the trend line I drew than any of the other points.

  2. Investigating how the length of wire affects the resistance

    The positively charged nucleuses stay where they are; however, they are still being attracted to the negative terminal. The electrons have to pass through the gaps in the stationary nucleuses in order to get to the positive terminal and enable electricity to flow.

  1. Investigating how the length of a Wire affects its resistance.

    When a thermisters is heated, the resistance is decreased because electrons in the semiconductor (silicon) are freed from its nucleus. This decreases resistance. If extreme accuracy is needed, a thermister can be used in conjunction with a suitable wire so that their effects cancel out i.e, because the resistance of

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

    I can conclude that this is the longest piece of wire I should use because if I used a longer piece of wire it may get too hot and then I may produce a curved graph that I know is incorrect.

  1. How length affects resistance in a wire

    I will keep this the same by using the same wire with the same thickness. This will allow me to keep a fair test the whole way through. Temperature- This is another variable that I will have to keep constant the whole way through my experiment.

  2. Length vs Resistance

    1.38 0.13 10.62 100 1.40 0.12 11.66 Before I carry out my main investigation, I decided to carry out a 'test' investigation, using the lengths, the thickness and the voltage that I have chosen for the investigation. I did this so that I can be sure that the diameter, lengths

  1. Find out what affects the resistance of a wire.

    First I will connect the analogue ammeter with the wire by using some leads and crocodile clips, then I will place the analogue voltmeter across the wire which will be placed on the heat prove mat[s]. Only then I will connect it to the supply (the lab pack)

  2. How the Length of a Wire Affects Resistance

    According to Ohm's law, the resistance is equivalent to the voltage divided by the current; therefore I think that as the length of the wire increases the resistance of the wire will increase as well. This will be because atoms of all conductors have free electrons in their outer shell.

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