• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month
Page
  1. 1
    1
  2. 2
    2
  3. 3
    3
  4. 4
    4
  5. 5
    5
  6. 6
    6
  7. 7
    7
  8. 8
    8
  9. 9
    9
  10. 10
    10
  11. 11
    11

An Investigation into how the Length of the wire affects its resistance

Extracts from this document...

Introduction

Jenny Arbuthnot

Physics Coursework

Aim:  An Investigation into how the Length of the wire affects its resistance

Research:

Resistance is a measure of how hard it is for an electrical current to flow through a conductor.  In a metal, current flows through the wire when a voltage is applied across the ends of the wire.  The current is free electrons flowing because one end of the wire is made positive.  The resistance will vary depending upon how easily the electrons flow through the wire.  The more difficult the electrons find it to flow through the wire, the higher the resistance will be.  Therefore, resistance can be thought of as how much energy is lost by an electron as it moves along a wire.

The resistance through a wire can be measured using the following equation, providing that the voltage and current passing through the component is known:

Resistance= potential difference (voltage) across a component

                Current through the component

image00.png

A Diagram showing the free electrons and positive ions inside a wire while a current is flowing.

Inside a metal wire, there is a regular array of positive ions.  There are also free electrons which travel in between the positive ions like gas molecules, so when a voltage is applied across the ends of the wire, the negative electrons are attracted towards the positive end of the wire and thus a current flows.

Wires have resistance because electrons cannot travel smoothly along it without bumping into the positive ions.

...read more.

Middle

8 Crocodile clips with good contacts or the resistance will be affected.  Crocodile clips secure the electrical wires to the components.

A Preliminary Experiment:

In this experiment, I am going to set up the following circuit in order to find out which lengths of wire and what current I am going to use in the main investigation.  This is how I am going to set it up:

image02.png

  I am using the variable resistor to make sure that the current within the circuit remains the same, even when the length of the wire changes.  In this experiment I am expecting to find out:

  • How much voltage the power pack should be set to in order for good results to be achieved but at the same time make sure that the wire does not overheat.
  • The different lengths of wire I should use in order for the difference between the results to be substantial enough to draw a graph that is easy to read.

Results of the preliminary experiment:

See handwritten sheet.

Method for the main investigation:

  • Set up the equipment as shown in the diagram below:

image02.png

  • I am going to make sure that there is a good connection between the components and the circuit.
  • I am going to make sure that all the components work (i.e. the voltmeter, ammeter and variable resistor) by firstly adding a bulb to the circuit.
  • I am going to measure the lengths along the wire using a ruler.
...read more.

Conclusion

  • I believe that as there were no anomalous results and the results were as I had predicted, the results are sufficient to be able to draw the conclusion that length and resistance are directly proportional.  If I had more time, I could check if the results were completely accurate by repeating the experiment again and making sure that I could reproduce the same results again.
  • If I were to carry on with this investigation and to explore resistance further, I would find the resistance of more lengths and I would try using more than just three currents.  This expansion of my investigation would support my results further.  Also, I would repeat the currents and the lengths that I did again to make sure that I could get the same results, which would support my conclusion of this investigation.
  • If I could improve on this investigation, I would change the type of ammeter and voltmeter that I used so that it would give a reading of more than two decimal places.  This would help give more accurate results.

Reference Books Used:

I used the following books in order to help me find the scientific knowledge:

  • ‘Physics for You’ by Keith Johnson
  • ‘Complete Physics’ by Stephen Pople

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

    Step 3 Sellotaped the E26 wire to the ruler at one end with a little wire extra from the ruler. This is to hold it still so that the length can measure accurately. Step 4 Straighten the wire and put the crocodile clip on 20cm.

  2. Resistance of a Wire Investigation

    Whilst unlikely (due to the two sets of results), this would cause a higher resistance as explained previously. However, it is now known, after researching the metal alloy "constantan," that the resistivity (the electrical resistance of a conductor of particular area and length)

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

    The material that the wire is made of (both in the circuit and for the wire being tested) The Cross-sectional area or diameter of the wire The length of all the wire in the circuit (excluding wire being tested) Preferably the equipment used including all the wires/wire.

  2. Resistance in a Wire Investigation

    This increase in collisions means that there will be an increase in resistance. "h Material : I think that the type of material of the wire will affect the amount of free electrons, which are able to flow through that wire.

  1. Free essay

    Resistance Investigation. My aim in this investigation is to measure the amount of resistance ...

    Material Volts on the voltmeter (v) Current (A) Resistance (?) Fractional data Decimal data (4dps) 10 Nickel chrome is used for all the lengths 2.3 1.20 23/12 1.9167 15 2.5 0.87 250/87 2.8736 20 2.4 0.69 240/69 3.4783 25 2.3 0.56 230/56 4.1071 30 2.2 0.48 220/48 4.5833 The results that were acquired from this preliminary

  2. Resistance Investigation

    The second law states that, starting at any point in a network and following any closed path back to the starting point, the net sum of the electromotive forces encountered will be equal to the net sum of the products of the resistances encountered and the currents flowing through them.

  1. --- PHYSICS INVESTIGATION ---

    5v 150 0.49 3.4 6.9 0.49 3.4 6.9 0.51 3.6 7.1 6.97 5v 160 0.46 3.4 7.4 0.47 3.4 7.2 0.48 3.6 7.5 7.37 5v 170 0.44 3.4 7.7 0.44 3.4 7.7 0.46 3.6 7.8 7.73 5v 180 0.41 3.3 8.0 0.42 3.4 8.1 0.44 3.6 8.2 8.10 5v 190

  2. The aim of this investigation is to discover how the length of a wire ...

    "sit" there while the current of electrons flows along, and some of the electrons collide with them. When an electron collides with an atom, some of the electrical energy it is carrying is transferred to the atom as kinetic energy.

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