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

Investigating the factors affecting the resistance in a piece of wire.

Extracts from this document...

Introduction

Helen Bewick 10C

Investigating the factors affecting the resistance in a piece of wire

Planning

Resistance- Resistance is a force which opposes the flow of an electric current around a circuit so that energy is required to push the charged particles around the circuit. Resistance is measured in ohms.

During this experiment I aim to research and plan an experiment to investigate a factor that affects the resistance in a piece of wire.

The possible factors I could change in this investigation are:

  1. Length of the wire,
  1. Thickness of the wire,
  1. Type of metal- Copper, Nichrome and constantan
  1. Shape of the wire,
  1. Temperature of the wire,
  1. Density of the metal.

I have chosen to investigate the length of the wire because length is a continuous variable with a continuous range so I will be able to choose any lengths to investigate.

I chose not to investigate thickness because although it is a continuous variable the wires available to me only come in set thickness that do not go up in regular intervals.

I chose not to investigate type of metal because it is not a continuous variable so I would not be able to evaluate the investigation by linking two or more groups of data on a graph.

I chose not to investigate the shape of the metal because it isn’t a continuous range. I could only use two options bent or straight.

I chose not to investigate the temperature because although it is a continuous range it is very difficult to maintain a temperature, as you couldn’t use a water bath because of safety aspects. It is also difficult to measure the temperature of a piece of wire.

...read more.

Middle

The resistivity of Nichrome at 250C is 100 x 10-8 ohm-m. The radius of the wire is 0.00014m2. To find the area of a cross section of the wire i use the equation for the area of circle

Area of circle = πr2

Area of circle  = π x 0.000142

Area of circle = 6.16m2 x10 -8

Working to find the resistance

To predict resistance for a length of wire of 10cm I use the equation,

Resistance  = resistivity x length / area of cross section of the wire

Resistance = 100 x 10-8 x 0.1m / 6.16m2 x 10 –8

Resistance = 1.62 Ω rounded 2 d.p.

To predict resistance for a length of wire of 20cm I use the equation,

Resistance  = resistivity x length / area of cross section of the wire

Resistance = 100 x 10-8 x 0.2m / 6.16m2 x 10 –8

Resistance = 3.25 Ω rounded 2 d.p

To predict resistance for a length of wire of 30cm I use the equation,

Resistance  = resistivity x length / area of cross section of the wire

Resistance = 100 x 10-8 x 0.3m / 6.16m2 x 10 –8

Resistance = 4.87 Ω rounded 2 d.p

To predict resistance for a length of wire of 40cm I use the equation,

Resistance  = resistivity x length / area of cross section of the wire

Resistance = 100 x 10-8 x 0.4m / 6.16m2 x 10 –8

Resistance = 6.49 Ω rounded 2 d.p

To predict resistance for a length of wire of 50cm I use the equation,

Resistance  = resistivity x length / area of cross section of the wire

Resistance = 100 x 10-8 x 0.5m / 6.16m2 x 10 –8

Resistance = 8.12 Ω rounded 2 d.p

To predict resistance for a length of wire of 60cm I use the equation,

Resistance  = resistivity x length / area of cross section of the wire

Resistance = 100 x 10-8 x 0.6m / 6.16m2 x 10 –8

Resistance = 9.74 Ω rounded 2 d.p

To predict resistance for a length of wire of 70cm I use the equation,

Resistance  = resistivity x length / area of cross section of the wire

Resistance = 100 x 10-8 x 0.7m / 6.16m2 x 10 –8

Resistance = 11.36 Ω rounded 2 d.p

...read more.

Conclusion

  • I left the power pack on too long. This causes the wire to overheat.
  • When I was measuring the lengths of the Nichrome wire my measurements might have been slightly inaccurate. The rulers used might not have been exact and it was difficult to get an accurate reading of length by eye as the wire was not completely straight. Also the ruler may have been of different thicknesses throughout the length. This would have contributed as a slight error in my results.
  • The ammeter and voltmeter could have been slightly faulty and not given me correct, accurate readings.
  • I connected the wire into the circuit using crocodile clips. These were quite loose and so this could have made my results less accurate. If I improved my method I could either attach the wires with tape but this may affect my results so instead I could solder the Nichrome wire into my circuit.
  • It was difficult to adjust the variable resistor slider accurately only by eye. If I did the investigation again I could try to and adjust the variable resistor accurately I will use an advanced digital variable resistor.
  • I also found it difficult to measure exact lengths against the meter rule because the crocodile clips didn’t clip on to the wire very securely. If I did the investigation again I could pre cut all the lengths of wire before the experiment instead of just connecting the crocodile clips at different distances apart on the meter rule.  

        To further my investigation I could use the same method but increase the range of lengths. I could use lengths of up to 3 meters. I could take readings from lengths at smaller intervals; I could take reading every 5cm instead of every 10cm as I did. I could also take more repeat readings to get a even more accurate average.

...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

    Resistance Aim: my main aim is to investigate the factors that affect the resistance ...

    3 star(s)

    material, its temperature, dimensions, and thermal properties; degree of impurity; the nature and state of illumination of the surface; and the frequency and magnitude of the current. The SI unit of resistance is the ohm (?). Resistors are devices, as a coil or length of wire, used in a circuit

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

    This led to the definition of one ohm: "A resistor has a resistance of one ohm, if a voltage of one volt will drive a current of one ampere through it". The resistance of a resistor is the voltage per unit of current, i.e.

  1. An Experiment To Find the Resistivity of a Wire

    The errors for the Resistance may be as a result of fluctuation in the Ammeter and Voltmeter used. EVALUATION I feel that the overall my results were quite accurate. Although the Resistivity of Constantan I found when I varied the length and cross sectional area were not the same for both with an error of 4.31%.

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

    Adjust the length by moving the second crocodile clip, keeping the first crocodile clip in place at the 10cm mark. Step 7 Then repeat steps 1-6 again but for the following wires E28 and E32. Factors In this experiment there was one variable which was not controlled and that was the length of the wire.

  1. The resistance of wire.

    wwef efw esefefs ayef efba nef kcef efuk. Apparatus -Power Supply, Ammeter,Voltmeter,Just over 100cm of E26 Wire,Meter Rule,Two Crocodile Clips,Connecting Wires. Factors which must stay constant to keep the experiment a fair test The power supply must stay on 4V, The wire must be the same thickness, The surrounding temperature must be constant, The equipment should be kept

  2. Length vs Resistance

    chosen length by 3, then the resistance of that length would be 3 times larger than the chosen length. In order to determine the relationship between the two variables, I had to find out five gradients (shown below), which will hopefully help me establish a pattern between length and resistance.

  1. Discover the factors affecting resistance in a conductor.

    Firstly, what we will change, and secondly, what we will keep constant. These in turn will determine the relation ship between the length of carbon putty and its resistance, and we may also observe certain other factors. Firstly, we need to state the control variable that we will change.

  2. Does Increasing the Length of a Nichrome Wire affect its Resistance

    Average Results Length of Copper Wire (cm) Average Resistance (ohms) 10 3.9306 20 7.983 30 11.356 40 14.841 50 18.4986 60 23.071 70 25.695 80 28.061 90 32.93 100 36.058 Analysis Looking through my graphs and tables I can see that the line has an upward trend of steepness and my resistance is increasing as I increase the length as well.

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