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

Investigate how the length of a wire affects its resistance.

Extracts from this document...

Introduction

Resistance of a wire Coursework Plan Aim To investigate how the length of a wire affects its resistance. Theory A current is a flow of charge. Electric current is the flow of electrons, usually in a wire. A current comes from cells or batteries, the electrons are already in the wire but have no charge. Current is measured in Amps using an Ammeter. The Ammeter must be placed in series with any components because it measured the current passing through it. To make a current flow you need a voltage. A cell or battery provides voltage. It is the energy that is needed to move a certain amount of charge (electrons) between two places. Voltage is measured in volts using a voltmeter. The voltmeter must be placed parallel to components because it is measuring the energy the electrons use up as they pass through the component. Electrical resistance is the effect a wire or component has on a current as it tries to prevent the current flowing through it. The electrons in a wire flow through the wire but there is a chance that they will collide and be slowed down by an atomic nuclei, this is resistance. The resistance of a length of wire is calculated by measuring the current present in the circuit (in series) ...read more.

Middle

0.58 3.94 3.92 3.92 3.93 0.15 40cm 0.65 0.66 0.65 0.65 3.82 3.80 3.80 3.81 0.17 50cm 0.74 0.72 0.76 0.74 3.39 3.38 3.36 3.38 0.22 60cm 0.78 0.81 0.78 0.79 3.17 3.23 3.18 3.19 0.25 70cm 0.82 0.85 0.85 0.84 2.82 2.83 2.82 2.82 0.30 80cm 0.84 0.86 0.86 0.85 2.72 2.73 2.74 2.73 0.31 90cm 0.91 0.93 0.91 0.92 2.39 2.46 2.46 2.44 0.38 100cm 0.92 0.92 0.94 0.93 2.44 2.43 2.44 2.44 0.38 I took three sets of readings so my results were as accurate as possible. I then found the average of all three results (add all three up and divide by three) and used Ohms law (R= V/I) to calculate the resistance in the wire. Conclusion As I predicted, an increase in length resulted in an increased resistance. The wire shows a strong trend of a straight line, i.e. the length of the wire is shown to be directly proportional to the resistance- double the length and the resistance also doubles. The increase in resistance is due to the longer length of wire and the electrons, which make up the current, have to travel past more of the fixed particles in the wire. This causes an increased number of collisions and therefore a higher resistance. A Short wire A Longer wire From this diagram you can see that the longer wire has more nucleus for the electrons to bump into therefore increasing resistance. ...read more.

Conclusion

This would give me a wrong result because the vibrating nuclei take up more room and therefore will let fewer electrons through. Extending the investigation To extend the investigation I could extend the range of lengths investigated and to see if the observed trend continued. I could also test alternative wires such as constantan or nickel chrome. I would do this to see if when the length of these wires is increased if the resistance also increased as it did with copper. I think that other types of wire would have different amounts of resistance because different wires have different densities. A denser wire would have more resistance because its nuclei are more tightly packed together, so the electrons are more likely to bump into the nuclei, thus causing more resistance. However I think other wires would still display the same trend as copper did (Resistance is proportional to length) I think this because an increase in resistance is due to the longer length of wire. The longer the wire the more fixed particles the electrons, which make up the current, have to travel past. This causes an increased number of collisions and therefore a higher resistance. If I did this experiment again, I would measure the wire using a millimetre ruler to keep any wrong lengths to a minimum therefore my results would be more accurate. I would also make sure I had let the wire cook completely before starting the next experiment. GCSE Physics coursework 1 Lucy Simmons ...read more.

The above preview is unformatted text

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. Electromagnet lab

    From graph 2, it can be clearly seen that it shows the effect of increasing the current on the strength of the magnet. From the graph we can see that most of the results are right as most of the results fall in a straight line.

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

    The current should be kept constant and the voltage varying according to the length of the wire. This is because the current is effectively the number of electrons flowing through the circuit. The resistance cannot be measured if the current changes as well because resistance causes voltage and current to decrease.

  1. To investigate how the length of a wire affects the current flowing through it.

    To try to gain a straight line we can re-arrange Ohm's Law- Step 1 Ohm's Law- V=IR So V=I R We then replace V (Voltage) with a constant of 1. So- 1=I or 1 I R R We know that: L=Length L R Step 2 We turn this into a

  2. How length affects resistance in a wire

    After looking at this I decided that we had to change something to our method. So for are next test I decided to lower the current through the circuit by using the rheostat. I thought this would help because I imagined that the voltage would not move around because there is less current flowing through the circuit.

  1. Free essay

    Investigation: How length affects the resistance in a wire.

    Firstly, after setting up my circuit, I double checked it against my diagram to see that it was set up properly. If I had not done this, then the readings would misrepresent what the actual voltage/current was, leading me to the wrong conclusion.

  2. Resistance Coursework

    30cm=0.95? and 40cm=1.124 ?. The theories behind these conclusions are: As the length of the wire doubles, the resistance also two folds. Resistance is caused by electrons bumping in to ions. If the length of the wire doubles, the electrons bump into the ions twice as much so the resistance will double.

  1. What affects the resistance of a wire?

    so that I am not vulnerable to any danger caused by the electrical equipment. We have been allocated the large power packs that have a facility incorporating a light that shows when the circuit is overheating. So if there is any danger we can immediately see that the circuit is overheating.

  2. The aim of my investigation is to investigate how length affects the resistance of ...

    This would mean I would obtain precise and reliable results in my main experiment when investigating the connection between the length of the wire and the resistance of the wire. First, the circuit was set up as shown below. I had to be careful in connecting circuit, because the Voltmeter

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