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

Investigating how thickness and length affect the resistance of particular wires.

Extracts from this document...

Introduction

Investigating how thickness and length affect the resistance of particular wires

Equipment

The equipment that I will need to perform this experiment will be:-

  • Battery pack
  • 5 Wires
  • A volt meter
  • An ammeter ( 0-15)
  • Crocodile clips
  • Ruler
  • Nickel chrome wire

image00.png

Method

The first thing that needs priority when setting up a circuit is safety. I will handle everything with dry hands and take extra care so that I don’t short circuit the experiment. The experiments will be investigating the relationship between the thickness of the wire and the length of the wire. I will connect up a circuit like shown above, the power supply coming from a power pack. A volt meter and an ammeter will be placed in series and the wire which I will be investigating, so will be changing, will run in parallel to the ammeter. The set up of the circuit will tell me exactly how much current is going through the circuit. With this information I can put the figures into an equation that will work out how much resistance that particular wire has. I chose to investigate length and thickness as they are both continuous as opposed to the type of wire which is -----. Once I have got the readings from the ammeter and voltmeter I can put the data into this equation.

Resistance (r) = voltage (v)

                                                Current (i)

I am going to measure the amount of current which passes through six different thicknesses of nickel chrome.

...read more.

Middle

Thickness

(SWG)

Thickness

(mm)

calculation

Average

(A)

20

0.90

(1.8 + 1.85 + 1.9) ÷ 3

1.85

22

0.71

(1.45 + 1.5 + 1.5) ÷ 3

1.48

24

0.56

(0.15 + 0.15 + 0.2) ÷ 3

1.17

26

0.45

(0.85 + 0.9 + 0.9) ÷ 3

0.88

28

0.37

(0.65 + 0.65 + 0.65) ÷ 3

0.65

30

0.31

(0.4 + 0.4 + 0.4) ÷ 3

0.4

To work out the resistance of each wire I am going to put in the average readings into the equation. The voltage was kept constant at 3volts so I’m going to divide 3 by each of the average readings.

Thickness

(SWG)

Thickness

(mm)

Calculation

Resistance

(  ) 1dp

20

0.90

3 ÷ 1.85

1.6

22

0.71

3 ÷ 1.48

2

24

0.56

3 ÷ 1.17

2.6

26

0.45

3 ÷ 0.88

3.4

28

0.37

3 ÷ 0.65

4.6

30

0.31

         3 ÷ 0.4

7.5

I have plotted a scatter graph of the results to see if there is a pattern. I am hoping that it will be inversely proportional where as the thickness in mm increases the resistance will decreases.

Length

Length (cm)

Result 1, amps (A)

Result 2,amps (A)

Result 3,amps (A)

10

1.5

1.5

1.5

20

0.85

0.85

0.85

30

0.6

0.6

0.6

40

0.45

0.45

0.45

50

0.4

0.4

0.4

60

0.3

0.3

0.3

70

0.25

0.25

0.25

80

0.225

0.225

0.225

90

0.2

0.2

0.2

100

0.15

0.15

0.15

...read more.

Conclusion

  The reason for the resistance to increases as the length increased is because the electrons have to travel further meaning there will be a lot more points where the electrons will be colliding with the ions. I can see that there the results increase at a curtain rate. I have worked out that the average resistance increase is about 1.8 ohms. When working out this calculation I dismissed the reading for 50cm as it was an anomaly.    

Evaluation

I personally think that the experiment went very well. The experiment proved what I originally thought would happen. The resistance increased as the thickness of the wire decreased. My results were very good as I seem not to have any anomilious data and they all support my prediction. I think that my results are quite accurate; the only thing that could have been inaccurate was the length of the wire as we had to keep changing the wires over. Even though I made sure I was as accurate as possible the results could have been 6.6% inaccurate due to the plus or minus 1 factor in the measuring.

  If I had more time to do the experiment I would have done some more repeat readings as there wasn’t enough time to do more than that three sets of results for each thickness of wire. I probably would change the length of wire is I got the chance to redo the experiment. I would make the wire longer, about 50cm or even 100cm. This will reduce the amount of possible inaccuracy as it would go down to 1% or 2%.

...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. Peer reviewed

    Investigation in resistance in wires

    5 star(s)

    Although there were no obvious outliers, I cannot point any out due to the fact that there is nothing to compare it to. Graph Conclusion During the preliminary you could see, feel and smell that the nichrome wire got very hot, this was a major problem because the temperature had to be constant.

  2. Investigating how thickness and length affect the resistance of a wire.

    Repeat steps 3,4,5 and 6 for the same thickness but a different length. 8. Once all the results for length have been taken using one thickness of wire, change the thickness and repeat steps 3,4,5 and 6. 9. Take repeat readings for every thickness and length in order to obtain more accurate readings.

  1. Investigate the resistance of different wires and how at different lengths the voltage increases ...

    As we already know only certain materials can conducts electricity because of the way the particles are arranged in that material as in those materials free electrons are given energy and they then collide with neighboring free electrons and this affect is carried on thorough out the wire which then

  2. Physics Coursework Investigating Resistance of wires and its relationship to length.

    I used Ohms law (V=IR, voltage = current �resistance) to work out the resistance. However V=IR does not tell me the resistance so I had to change the equation to R=V/I (resistance = voltage � current) in order to get the resistance.

  1. Resistance and Wires

    This increase in resistance changes the recordings of data by increasing potential difference and therefore increasing resistance. This would have make the test unfair and caused the results to be inaccurate and unreliable. This factor had to be controlled during each area of investigation.

  2. Resistance of wires

    Note: Ohm's Law only applies to metallic conductors. But the factor we need to pay attention to during this case is the temperature, as Ohm's law states that in order for the potential difference and current to maintain proportional, the temperature must remain constant. It is challenging for us to keep such steady conditions, but is not unmanageable, and nothing should go wrong if precautions are taken.

  1. Resistance of Wires

    This means that electrons will find it harder to pass through the circuit, which would increase the resistance. > the type of wire - Atoms of different elements will impede the electrons by different amounts; for example electrons pass easily through copper wire, so resistance there is less, but much less easily through nichrome wires, so resistance there is more)

  2. Objective: to investigate how the rate of resistance is affected by the different thicknesses ...

    will not collide with the nuclei's frequently as there are not many, resulting to a decrease of the resistance of the wire. Four factors affecting the resistance in a circuit: 1. Length of Wire The longer the wire, the higher the resistance.

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