• 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 Metal Wire.

Extracts from this document...

Introduction

Physics AT1: Factors Affecting the Resistance of a Metal Wire.

Planning.

I am going to test which factors affect the resistance of a metal wire, of which there are four, these are: the length, the type, the width and the temperature of the wires. I will use the equation I=V/R to work out the resistance of the wires, after finding out the voltage when the current is altered.

I will use a variable resistor to vary the current throughout the circuit and take readings of the voltages corresponding to that current.

In order to make this experiment fair; I will keep the width, temperature and type of wire constant. I shall investigate the changes in resistance when the length of the wire varies as this is the easiest variable to change because monitoring temperature is difficult, as is being certain of the width of a wire. I am not changing the type of wire because we do not have many different types available to us in school. I will keep the current small so that the wires do not overheat; otherwise there will be another change in variables. The increase in the temperature is dangerous, which is why this variable is kept constant.

...read more.

Middle

Copper wire has a low resistance, therefore, voltages are too difficult to read, which is why this type of wire shall not be used in this experiment.

Nichrome wire of diameter 0.457mm  is the better of the three wires to use because the values are clearer to read. There is a smaller resistance and it does not exceed the maximum voltage (3 x 0.85V = 2.55V).

I shall use Nichrome wire of diameter 0.457mm for this experiment. The temperature will remain constant so this cannot affect experimental values of the resistance. I will maintain the temperature by using a low current and I using lengths of wire above 20cm to prevent the wire from overheating.

The maximum length of wire available for use is 3m (300cm). I shall use lengths 40cm, 80cm, 120cm, 160cm, 200cm, 240cm, and 280cm. This covers the majority of the wire length. I have chosen seven values because when the average resistance is plotted on the graph, it is more accurate and clearer to read.

I shall measure the voltage, and then  calculate resistance, for each current three times in case any anomalies appear. Should there be an anomaly, I will take the average of just two values and exclude the anomaly.

...read more.

Conclusion

The voltages in my table hardly ever reached over 2V so if I carried out this experiment again, I would prefer to use a range of sensitivity 2V for more accuracy.

This experiment could be carried out using data-logging to both speed it up and to give more accuracy. I could also use different wires to see if my conclusion is true for other types of metal wires.

The points plotted on my graph were very close to my line of best fit, proving that the length of wire and the average resistance are directly proportional.

There was one anomaly within my results, which I have highlighted. When the reading was taken, the wires were touching, causing it to short-circuit. Next time, for more accurate results, I would make sure the wires were not touching.

For greater reliability, I could do more repeats, although I think if I did do more repeats, they would be very similar to those I have already taken.

I think my evidence is sufficient to support a firm conclusion that resistance is directly proportional to the length of a metal 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. Marked by a teacher

    The factors affecting the resistance of a metalic conductor.

    4 star(s)

    the length of the wire is actually increased and the electrons flowing through it will have a longer distance to travel and thus the resistance will be increased. PARALLEL CIRCUITS: In a parallel electrical circuit, the components share an energy source but do not share the same current.

  2. Factors Affecting the Efficiency of a Wind Turbine

    It produced a graph with a shape that was changing continuously. TABLE OF RESULTS FOR BLADES A, B and C BLADE TYPE VOLTAGE OUTPUT RECORDED (mV) BLADE a 0 BLADE b 227 BLADE c 28 Discussion of results Results have confirmed my expectations in this instance.

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

    So the background radiation is probably higher than expected which caused some of the values in the table to go into the negative values. Another explanation is that there were experimental errors when doing the experiment. Accuracy and Reliability - Because of these anomalies, I don't think that the results were reliable enough to support a firm conclusion.

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

    proportion to the width" From my graph I have shown that my prediction was correct, as the Line of Best Fit is a straight line proving that the resistance of the wire is proportional to the width of the wire.

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

    For example, the resistance of some conductors will alter if they are bent or placed under tension or if put at right angles to a strong magnetic field. It is also important to remember that Ohm's Law only works with metal conductors.

  2. Discover the factors affecting resistance in a conductor.

    conductor, but copper, the next best, is cheaper and is used for connecting wire in electric cables. Resistance is used to control the amount of voltage and amperage in a circuit. Everything in the circuit will cause a certain amount of resistance.

  1. Factors affecting Resistance of a wire

    This experiment requires safety considerations. Only use low voltages, because the wire will not be able to cope with very high ones. Do not use more than 4V for very long at a time. Set up the circuit as shown on the above diagram, excluding the voltmeter.

  2. Resistance and Wires

    2d.p, but it is the most accurate reading of 'n' that I can conclude with. This value of 'n' can be used for any length due to the fact that the relationship between length (y) and resistance (x) is always directly proportional.

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