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

Aim: The aim of this experiment is to see how the length of a nichrome wire affects its resistance.

Extracts from this document...

Introduction

Resistance in a wire                  Prasal. S. Rohra
                                                                                               IX-B

Introduction: Resistance is the force which opposes the flow of an electric current around a circuit. Resistance is measured in ohms (image00.png). Resistance involves collisions between the free electrons, the fixed particles of the metal and its impurities. This collision creates friction due to which some of the energy the free electrons are carrying is converted into heat. Resistance can be measured using the Ohm’s Law (named after Georg ohm): -

Resistance of a wire can be affected by various variables like thickness, purity, temperature, material and length out of which length is an important one. There is a direct relationship between the length of a wire and its resistance because as the length of a wire is doubled so is the resistance. As resistance is a result of collisions between the free electrons and the fixed molecules of the metal of a wire, there will be more collisions if there is a longer wire (as it is a longer path to travel for the electrons).

...read more.

Middle

Length (cm)
(1.d.p.)

Voltage (V)
(1.d.p)

Current (A)
(3.d.p)

Avg. Current(A)
(1.d.p)

Resistance (image00.png)

...read more.

Conclusion

If I would do the experiment again I would also investigate other factors, such as temperature, voltage and current, and see how these affect the resistance.

--------------------------------x---------------------------x----------------------------x----------------

...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

Here's what a star student thought of this essay

4 star(s)

Response to the question

The author answers the question set thoroughly and with a good explanation of how the science involved would create the given results. They conduct several repeats of their measurements, which is helpful as it allows anomalies to be seen and ...

Read full review

Response to the question

The author answers the question set thoroughly and with a good explanation of how the science involved would create the given results. They conduct several repeats of their measurements, which is helpful as it allows anomalies to be seen and means errors can be averaged out. The author mentions crocodile clips being incorrectly positioned as a possible cause for error, and taking repeat measurements as a way of removing this problem, but this would only be the case if the clips were repositioned each time. An easy way to ensure the wire lengths from which the resistance is measured is accurate would be by cutting them longer than required and marking the lengths on with permanent marker. When cutting the wire keeping it taut between two clamps would ensure the correct length was cut.

Level of analysis

The author’s level of analysis was good, but it could have been improved by adding more detail. The explanation of how resistance works was simple and effective, and I think it would have been more so had the intended diagram appeared in its complete form. At GCSE level I don’t think I would have added much to this, but a description of resistivity might have added to the piece. While resistance is a property of the wire (it is affected by length, diameter etc), resistivity is a property of the metal itself. The author could have checked her results using this, allowing them to come up with a greater idea of the uncertainty in their results. By multiplying the resistivity of the metal by the length of the wire and dividing by its cross sectional area, the author would have a measure of the expected resistance for that piece of wire, and could look at how her results varied from this. This would take their work beyond the content of the syllabus, showing that they read around the subject. The author should have looked into using a different power source if theirs kept shorting out, as only putting the equipment on for short periods of time would not give the readings time to settle. Alternatively, they could have changed the length of wire so the power source did not cut out. If I had conducted this experiment I would have done some preliminary plans to check the length of wire and equipment required. There was no circuit diagram visible in this piece, and this is necessary in a piece of coursework (as is the missing graph), but the former was certainly implied and if this was correct would have been a useful addition to the piece.

Quality of writing

The spelling, punctuation and grammar of this piece is generally good, with scientific vocabulary used to good effect. Generally the piece read fluidly, but sentences such as “The good thing I did in the investigation was that...” could have been reworded so that the piece read better. This is a minor concern, and though it would probably not affect the writer’s mark directly, if the whole piece reads well it gives the impression that the science itself is better.


Did you find this review helpful? Join our team of reviewers and help other students learn

Reviewed by E13 16/02/2012

Read less
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. To investigate which fuel gives out the most energy when burnt. We are burning ...

    They both show a positive correlation once again supporting my prediction. The experiment was carried out correctly and successfully, I can say this because of the lack of anomalous points. Pentanol is the alcohol with the longest chain of molecules so therefore it has more bonds to break and more to be made.

  2. Electromagnets - What factors affect strength of an electromagnet?

    The anomaly may also have been resulted, because the iron bar might have sided out slightly, causing the magnetic field to weaken. During both of the experiment I also observed number of things. During the first experiment I noticed that, when the power pack was switched off on a particularly

  1. To find out what happens to the efficiency of a motor as I change ...

    I also drew a sample of what I thought my line of best fit would look like. This turned out to be partially correct: the real line of best fit clearly shows the efficiency decreasing, but only after an initial increase before reaching 0.6N. My graph backs up these comments.

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

    room temperature as possible and waiting for a few minutes before I take my next reading to let the wire cool down). > The same voltage was used throughout the experiment. > The same apparatus-for example voltmeter, an ammeter, wires, variable resistor, power pack and crocodile clips.

  1. Free essay

    Aim: the aim for this experiment is to check if the length of a ...

    Do the same for all the ranges. 7. Carry out the same for the copper wires. Result table Types of wire Copper Wire Nichrome Wire Length of wire Current (in Amps) P.D (in Volts) Resistance Current (in Amps) P.D (in Volts)

  2. The Bouncing Ball Experiment

    rulers, and they stand in exactly the same place for each experiment. This is why the same person drops the ball each time. This is why the rulers are held as straight as possible by two people to prevent human error in reading the results.

  1. To investigate how a height of a ramp affects the speed of a trolley ...

    The method that I used was quite a reliable one and there were not very many problems that occurred from carrying out the experiment, The amount of energy loss from heat and sound when letting the trolley/car down the ramp was more than I expected.

  2. Solar Cell Investigation.

    There must be an increase in resistance. Current flowing through the conductor may encounter resistance. Any resistance they encounter inside the source is called the internal resistance which has removed energy from the charges before they have a chance to leave the source. This basically means wasting the source's energy.

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