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

Investigating how the length of a wire affects the resistance.

Extracts from this document...








The aim of my investigation is to find the relationship between the resistances of a wire at different lengths. An electric current in a wire is a flow of electrons and can be measured in amperes. Resistance is the natural property of all conductors to hinder an electric current.


In this investigation I will set up a simple circuit to read the voltage and current when the length of the wire changes. The length will range from 10cm - 60cm with intervals of 10cm. Moving the crocodile clip across the wire on a ruler will change the length of the wire. For each of these lengths I will find the potential difference across the wire length and the current flowing through it. I also decided that the best thickness of wire to use would be 30swg.This is because a thicker wire would cause too much heat, and the resistance of a thinner wire would be high and difficult to measure. The reason for this is that a thicker wire has less resistance, because there is more room for the electrons to travel through it.

The readings from the ammeter and voltmeter will be used to work out the resistance. This can be done using the formula: R = V/I (Ohm’s Law)                                                                                                                                                               V=voltage (Volts) I=current (Amps) R=resistance (Ohms)

Variables                                                                                  For this investigation I am going to have dependent and independent variables.

...read more.


The circuit should be set up as in the circuit diagram. It is important that the voltmeter is set up in parallel and the ammeter in series.





Preliminary work                                                                       I did a preliminary test as a trial of my investigation for the following reasons; to get an idea of the results and the range of value I would be working in, to get used to the equipment, to ensure that the wire did not get too hot, and to test the amount of cells to used in the circuit. The amount of voltage I used was important, as it would determine how hot the wire got. If the wire got too hot, energy would be given off as heat, and the resistance would have increased. I did a test that used the same piece of wire at different lengths with 1 and 2 cells. The results showed that with 2 cells, the resistance was higher due to the wire being hotter. For this reason I will use 1 cell to keep it a fair test. I needed to repeat the result for accuracy and reliability.

...read more.


Through out my investigation I found that I had anomalous results so I redid the test of 60cm, as the average resistance was 20.1 I found this result was too high to be reliable. This anomalous result could have been caused because of the wire heating up. I had a considerable amount of anomalous results, which lead me to feel that my results weren’t sufficient enough. Even though my results weren’t perfect, in that they don’t follow a set pattern, they do give me the information I need to prove my prediction. If I had to do the practical again I would improve it by keeping the current switched off for longer to ensure that the wire stays at the same temperature and repeating the readings more often. I would have also taped the ruler to ensure that it stayed in the same place and didn’t move. I also found that I could have used a copper wire instead of a Nichrome wire. However, Nichrome wire has more resistance but I would’ve had to do a further investigation to prove this. For further work I could have done an experiment to prove that Nichrome wire has more resistance than a copper wire.

...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. Resistance of a Wire Investigation

    Plant- Different species plants have different photosynthetic rates due to the different leaf structures of the plants. Even plants of the same species may have slightly different rates of photosynthesis since there may be more or less chlorophyll in the leaves to absorb light.

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

    This can be greatly helped by doing all of the experimentation in one go and using the same equipment throughout it. Different equipment can lead to different results. This is because the resistance of the circuit can change when different equipment is used which can affect results.

  1. Free essay

    Investigation: How length affects the resistance in a wire.

    Ultimately, I will use these two aspects to find out the resistance that the wire experiences, using Ohm s law of voltage divided by current equals resistance. Prediction: I predict that as I increase the length of my wire, the resistance will increase; there is greater distance for the current to travel through.

  2. What affects the resistance of a wire?

    We did the experiment using a copper wire and a constantan wire, taking the readings at every 10cm. The results were recorded: CURRENT = 0.20 AMPS Length (cm) Copper Wire Constantan Wire PD (V) Resistance () PD (V) Resistance ()

  1. Investigate how length affects the resistance of a length of wire.

    Length (cm) Current (Amps, A ) Voltage (Volts, ) Resistance (Ohms, ) Average resistance (Ohms, ) 50 0.340.300.520.330.44 1.411.361.491.131.02 1.54 40 0.340. 1.28 30 0.960.950.930.911.00 0.97 20 0.350. 0.660.690.660.660.71 0.68 10 0.370.320.380.310.29 0.33 Main Experiment Prediction I predict that if the length

  2. Investigation on Photovoltaic Cells

    I am aware that external factors may make my experiment unfair and even inaccurate. To overcome this problem I have decided to do my experiment in a cardboard box. This will hopefully eliminate any light that is not coming from the lamp.

  1. Construct and test an anemometer.

    be able to produce a calibration curve for the relationship between potential difference created by the motor and wind speed. To record the rpm of the cups I had initially intended to use light gates, and to record three interruptions per revolution.

  2. "Are rechargeable batteries more economical than alkaline batteries?"

    By approximately 10hrs, both remaining battery was removed. All three trials were nearly identical; the brightness and duration of each of the bulbs where quite predictable by the third trial. Limitations: The limitations of this experiment are due to three main factors: 1.

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