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

I hope to find out how resistance of a wire is affected.

Extracts from this document...


Jason Berry 11H


Aim: - I hope to find out how resistance of a wire is affected.

Prediction: - I predict that as the length of the wire increases the resistance will also increase.

Scientific Knowledge: -

  A wire is a bundle of metal strips coated in plastic. The plastic can vary in colour and connect to different terminals

  These are: -

  • Black = negative terminal
  • Red = positive terminal
  • Blue = neutral terminal
  • Green and yellow = earth terminal
  • Brown = live terminal

The material varies because it has free electrons, which are able to flow through the wire. The number of the electrons depends on the amount of electrons in the outer energy shell of the

...read more.



Ohm's Law

The law actually says that the resistance of a metal conductor is the same whatever the current - unless it’s getting hotter. However most people think of these equations when the law gets mentioned:

V = IR

V is Voltage in Volts, I is Current in Amps and R is resistance in Ohms.

If the length of the wire is increased then the resistance will also increase as the electrons will have a longer distance to travel and so more collisions will occur. Due to this the length increase should be proportional to the resistance increase. If the wires width is increased the resistance will decrease. This is because of the
increase in the space for the electrons to travel through.

...read more.


  • D.C (Direct Current) is where the current always flows in the same direction. Cells and batteries supply a D.C. current.



  1. Set up the circuit as shown above WITH THE POWER SWITCHED OFF
  2. First use a piece of wire of one meter in length then move the crocodile clips towards each other to the appropriate length; 90cm, 80cm 70cm, 60cm, 50cm, down to 10cm. This means you will have 10 results.
  3. Turn the power on to 2 volts, then take a reading of the ammeter and the voltmeter
  4. Before shortening wire to 90cm, allow two minutes for the wire to cool down because it will be very hot to touch and it would also be a unfair test.
  5. Repeat the above until length is 10cm
  6. Repeat the whole investigation for Reliability

...read more.

This student written piece of work is one of many that can be found in our AS and A Level Electrical & Thermal Physics 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 AS and A Level Electrical & Thermal Physics essays

  1. Exploring the resistance of a wire

    wire in to the power supply, so that no current flows while I am connecting the circuit, and then I would carry on that way plugging the voltmeter parallel to the bulb after that I would plug in the ammeter in the circuit then plugging the wire from the ammeter into the power pack.

  2. resistivity if a nichrome wire

    2.71 1.11 0.800 0.001 3.11 0.240.01 0.24 4.17 % 3.11 0.005 3.11 0.16 0.900 0.001 3.51 0.240.01 0.24 4.17 % 3.51 0.01 3.51 0.28 1.000 0.001 3.92 0.240.01 0.24 4.17 % 3.92 0.015 3.92 0.38 Current percentage error The current was a constant reading all they way throughout the circuit.

  1. Investigating the effect of 'length' on the resistance of a wire

    Repetition would produce maximum reliability of results. If the second reading is similar to the first then the first confirms the second and vice-versa, if somehow two results are not similar then I will repeat it again until two results are similar, and these two results will be averaged.

  2. Free essay

    Resistance of a wire

    * Always switch off equipment after you have finished using it or between each measurement to allow the wire to cool. * Never use faulty equipment, report it immediately to a member of staff. * Keep gangways clear of obstructions.

  1. Investigating how temperature affects the resistance in a wire

    Turn on the multimeters and make sure they are recording the appropriate measurement (i.e. volts or amps) and that they are functioning properly. 6. Fill up the 250-ml measuring beaker with cold of water from the tap till the water bath is at 10?C, and then quickly record the volt and amp readings from the two multimeters.

  2. Finding the Resistivity of a Wire

    o I will use Nichrome wire, as it produced good results in my preliminary work o I will use the fixed current and the voltage readings taken to find the resistance of the wire at the different lengths, using the formula o I will use the diameter of the wire

  1. Find The Internal Resistance Of A Power Supply

    Readings of voltage and current will be taken from the voltmeter and ammeter. Which Variables Will Be Changed and Which Kept Constant: The variable resistor will be used to change load resistance in the circuit by moving the sliding contact along in order to record several values of current and

  2. Coursework To Find The Internal Resistance Of A PowerSupply

    As the current flowing through the power supply increases, the lost volts will increase. If the current decreases, then the lost volts also decreases until the current is zero. At this point, the potential difference across the terminals of the power supply will be equal to its EMF.

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