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

What factors affect the resistance of a wire?

Extracts from this document...


Amie Mustill

What factors affect the resistance of a wire?

Although the current and the potential difference (voltage) measure different things, they are related to one another. If a battery is connected to a length of wire, it is possible to measure the current through the wire using 1, 2, 3 or 4 cells. By doing this, it is possible to find a simple relationship between the potential difference across the ends of a wire and the current through it. This being that doubling the potential difference doubles the current. Repeating the investigation for other types of wires provides results displaying a similar relationship between potential difference and current. Voltage current graphs are always straight lines through the origin, although the slopes are different. In 1826 a German physicist called Georg Ohm first discovered this relationship between potential difference and current. Ohm’s law states that:

“Provided the temperature and other physical factors remain constant the current

through a wire is proportional to the potential difference across its ends.”

If the potential difference across the ends of a wire is divided by the current through it, we get a constant figure for a given piece of wire. This figure is the resistance of the wire and represents the wires opposition to current. Ohm’s law can

...read more.


  • 1 piece of constantan wire of length 110cm
  • 2 crocodile clips
  • 2 red leads
  • 2 black leads
  • A power pack (plugged into a power supply)
  • Digital voltmeter
  • Digital ammeter
  • Metre rule


Before I begin the experiment I will set up the required equipment as displayed in the diagram above. Once all of the equipment is in place I will begin by placing the crocodile clips (attached to the leads) 10cm apart (measure using the metre rule) along the 0.3mm diameter piece of constantan wire. I will then turn on both the digital ammeter and digital voltmeter, before switching on the power supply, followed by the power pack, which should be set at 3 volts. I will then record the readings that both the voltmeter and the ammeter display before switching off the power pack. Having recorded measurements for the voltage and the current I am then able to use the formula R= V/I

(R= resistance (ohms), V= Voltage (volts), I= Current (amps)) to work out the resistance across the wire. Once the readings have been recorded and the resistance calculated, I will repeat the procedure twice (total of three). I will then carry out the same procedure when the crocodile clips are 20cm, 30cm, 40cm, 50cm, 60cm, 70cm, 80cm, 90cm and 100cm apart. Once all ten measurements have been completed, I will repeat the experiment a further two times (total of three) using two different piece of 0.

...read more.


The results that I obtained whilst finding out what affects the resistance of a wire were both accurate and fair and corresponded to the secondary evidence that I had found. I came across irregular results whilst carrying out preliminary experiments. These anomalies were due to the high resistance, which increases the temperature of the wire and affects the resistance. However, this allowed me to decrease the resistance for my final experiment and as a result I did not come across any anomalies and in many cases I recorded the same resistance for a length of wire more than once. Therefore, I feel that the results that I have collected are sufficient and support my conclusion.

The experiment that I performed was very suitable and it produced accurate results, but if I were to perform it again, I would improve it by:

  • Finding a better method of measuring the distance between the two crocodile clips because I do not feel that using a meter rule was accurate enough
  • Testing a wider range of measurements
  • Use the actual lengths of wire rather than measuring the distance between two crocodile clips

There are many other experiments that I could perform in order to find out what affects the resistance of a wire, such as:

  • The diameter of the wire
  • The type of wire
  • The temperature of the wire
  • The voltage
  • Test a wider variety of measurements



Advanced Chemistry for you                                Lawrie Ryan        

AS Chemistry                                                Andrew Hunt

AS Chemistry                                                Rob Ritchie

Chemistry in Context                                        Graham Hill And John Holman                                                                                                                           

...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. Resistance of a Wire Investigation

    spectrum but not the green light in the middle, which is reflected back. If the light level is raised the rate of photosynthesis will increase steadily but only to a certain point. Water is important because it is needed to join with CO2 molecules to make glucose and the amount

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

    Take 5 readings for each length of wire. Step 6 Then repeat steps 1-5 again but for the following wires E28, E30, E32, E34, and E36. Factors In this experiment there was one variable which was not controlled and that was the cross sectional area of the wire.

  1. Discover the factors affecting resistance in a conductor.

    voltage differed and a rough estimate of the results shown had to be displayed. Therefore if I were to repeat the investigation I would avoid using the voltmeter and ammeter, but just use the multimeter. One problem I encountered in the multimeter graph was that the line of best fit did not pass through the origin.

  2. The resistance of wire.

    I think that according to each individual wire, the resistance will be different, to gain a helpful prediction, some more background information must be achieved. wwcb cbw escbcbs aycb cbba ncb kccb cbuk: wwec ecw esececs ayec ecba nec kcec ecuk.

  1. What Factors Affect The Amount Of CurrentThat Can Flow Down A Wire

    This means the resistance is doubled. The total resistance of resistors in series is the sum of the resistance of each one. Each cm of wire has a particular resistance, if you double the length of wire; it is like having two of the shorter wires in series.

  2. What factors affect the flow of current through a wire?

    * Ammeter - This records the current of the circuit. * Voltmeter - This records the voltage of the circuit. * Variable resistor - This changes the resistance of the circuit * Constantan wire (0.9mm) - This is what I am testing.

  1. Investigating The Factors Which Affect The Resistance In A Wire

    0.07 4 40 0.65 7.41 0.09 We tested for which wire out of nickel and copper was the best to work with and we found that nickel was the best to work with because it was the least unstable whereas the figures from copper kept on changing rapidly so we were not able to get reliable results from that.

  2. Factors which affect the resistance of a wire

    of wire (measured in mm) (Standard wire gauge) - Starting temperature of wire - Voltage across wire - Current in circuit - Temperature of wire There are five factors that can affect the rate of resistance: - The length

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