• 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)

    wire into the circuit Nichrome wire - The independent variable Ammeter - To measure the current in the circuit Voltmeter - To measure the voltage, as the power pack is less accurate Variable resistor - To reduce the problem of heat Retort stand - To attach the clamp to Clamp

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

    In addition, if the length of the wire was trebled or quadrupled, then the resistance would also treble or quadruple. From the graph it is easy to tell that the theory is correct and therefore my results reliable. From my results table and graph, I can see that my results that I collected are quite reliable and accurate.

  1. 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.

  2. Resistance and Wires

    For this experiment, a factor that could affect the resistance of the wire, and which is not a variable in this experiment is the heat of the wire. This factor is a major reason for resistance in hot wires and is a factor which I am not intending to record the effects of, in this investigation.

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

    Range of observations For my experiment I shall be doing 7 different lengths of wire with three checks each and I will be doing two in-between experiments with three checks each and that shall be for each of the four types of wire.

  2. Why is there resistance in wires, and when you differ things like the extent ...

    The thickness - the thicker the wire is the less resistance it has and the thinner the wire the more resistance it has. This is because in the thicker wire the electrons have more room to move through the wire and in the thinner wire they have less causing more resistance.

  1. Planning Experimental Procedures

    I also labelled each of the wires as soon as they been cut to avoid confusion. I believe that I controlled the variables quiet well. The results are reliable because they are similar to the secondary results and also they match my scientific knowledge.

  2. Resistance of wires

    Another way to work out the many different calculations in physics is to use this excellent diagram, also discovered by George Ohm. (I extracted it from a physics website In this useful and valuable formula grid, George Ohm exposed how to calculate and work out different equations to be applied

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