• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month
Page
  1. 1
    1
  2. 2
    2
  3. 3
    3
  4. 4
    4
  5. 5
    5
  6. 6
    6
  7. 7
    7
  8. 8
    8
  9. 9
    9
  10. 10
    10
  11. 11
    11
  12. 12
    12
  13. 13
    13
  14. 14
    14

Factors affecting Resistance of a wire

Extracts from this document...

Introduction

Factors affecting Resistance

In preliminary work, I wanted to find out which factors affect resistance. In some research I found that there were four factors. The four factors of resistance are:

  • Temperature: If the wire is heated up the atoms in the wire will start to vibrate because of their increase in energy. This causes more collisions between the electrons and the atoms as the atoms are moving into the path of the electrons. This increase in collisions means that there will be an increase in resistance.
  • Material: The type of material will affect the amount of free electrons, which are able to flow through the wire. The number of electrons depends on the amount of electrons in the outer energy shell of the atoms, so if there are more or larger atoms then there must be more electrons available. If the material has a high number of atoms there will be high number of electrons
    causing a lower resistance because of the increase in the number of electrons. Also if the atoms in the material are closely packed then the electrons will have more frequent collisions and the resistance will increase.
  • Wire length: 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.
  • Wire width: 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. Due to this increased space between the atoms there should be fewer collisions.

This can be explained using the formula:

R=V/I

Prediction

I predict that the longer the wire, the higher the resistance.

...read more.

Middle

0.289617486

40

0.74

0.72

0.71

0.72

1.9

1.8

1.8

1.83

0.393442623

50

0.92

0.89

0.89

0.90

1.9

1.8

1.8

1.83

0.491803278

60

1.09

1.10

1.07

1.09

1.9

1.8

1.8

1.83

0.595628415

70

1.30

1.27

1.25

1.27

2.0

1.8

1.8

1.87

0.679144385

80

1.44

1.41

1.44

1.43

1.8

1.8

1.8

1.80

0.794444444

90

1.58

1.59

1.60

1.59

1.8

1.8

1.8

1.80

0.883333333

100

1.86

1.75

1.76

1.79

1.8

1.8

1.8

1.80

0.994444444

[Hand drawn graph here]

Table & Graph for 26 SWG

Length (cm)

26 SWG volts

26 SWG amps

Average

Resistance (Ω)

Test 1

2

3

Average

Test 1

2

3

Average

Measured in seconds

Measured in seconds

10

0.35

0.28

0.30

0.31

0.4

0.4

0.4

0.4

0.775

20

0.56

0.54

0.55

0.55

0.4

0.4

0.4

0.4

1.375

30

0.91

0.84

0.87

0.87

0.4

0.4

0.4

0.4

2.175

40

1.21

1.06

1.15

1.14

0.4

0.4

0.4

0.4

2.850

50

1.52

1.32

1.40

1.41

0.4

0.4

0.4

0.4

3.525

60

1.82

1.59

1.70

1.70

0.4

0.4

0.4

0.4

4.250

70

2.15

1.88

2.00

2.01

0.4

0.4

0.4

0.4

5.025

80

2.43

2.17

2.30

2.30

0.4

0.4

0.4

0.4

5.750

90

2.73

2.44

2.60

2.58

0.4

0.4

0.4

0.4

6.450

100

3.0

2.66

2.88

2.85

0.4

0.4

0.4

0.4

7.125

image01.png

Table & Graph for 28 SWG

Length (cm)

28 SWG volts

28 SWG amps

Average Resistance (Ω)

Test 1

2

3

Average

Test 1

2

3

Average

Measured in seconds

Measured in seconds

10

0.29

0.30

0.30

0.30

0.2

0.2

0.2

0.2

1.50

20

0.60

0.60

0.59

0.60

0.2

0.2

0.2

0.2

3.00

30

0.89

0.92

0.88

0.90

0.2

0.2

0.2

0.2

4.50

40

1.15

1.24

1.21

1.20

0.2

0.2

0.2

0.2

6.00

50

1.39

1.53

1.50

1.47

0.2

0.2

0.2

0.2

7.35

60

1.78

1.84

1.82

1.81

0.2

0.2

0.2

0.2

9.05

70

2.10

2.14

2.11

2.11

0.2

0.2

0.2

0.2

10.55

80

2.37

2.45

2.45

2.42

0.2

0.2

0.2

0.2

12.10

90

2.73

2.76

2.75

2.75

0.2

0.2

0.2

0.2

13.75

100

2.97

3.04

3.03

3.01

0.2

0.2

0.2

0.2

15.05

image02.png

...read more.

Conclusion

The only way we would be able to solve the problem of the bends and twists in the wire is to use a brand new piece of wire and look after it very carefully. We could solve the length problem by using a brand new piece of wire, which starts off at 1m in length, and we would cut it down to size for each result. This would make our observations closer to the exact length.

Our results were also made more accurate by the fact that we used a fairly wide range. Using just one or two increments is not reliable enough to draw a valid conclusion, so we used 10 increments. This way we would have been able to cope with any anomalous results using a line of best fit.

Anomalies could have been because the temperature became too high, creating an extra variable to make the test unfair. If the temperature did get too high it would have decreased the current, increasing the resistance. Similar to this idea, the wire could have had some impurities in it, varying the resistivity and increasing/decreasing the resistance. Any of the remaining three (I say this because we have already used one in our experiment - length) factors affecting resistance could have been varied - temperature, resistivity and thickness, leading to unreliable readings. The other reason for an anomaly could simply be that we misread the voltmeter/ammeter.

We could use an even wider range of results to increase the reliability of out results, or we could repeat the results more times. For further work, we could think about which material, length, width and temperature wire has the highest/lowest resistance. We could also use different kinds of resistors in the circuit, for example thermistors, so we could see how resistance varied with heat and that resistor, or we could instead use a light dependant resistor, to see how resistance would vary with that.

...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. Marked by a teacher

    Resistance Aim: my main aim is to investigate the factors that affect the resistance ...

    3 star(s)

    79.60 0.45 7 5.28 94.65 95.10 94.20 0.50 8 Average = 5.70 And now I will draw a graph representing current against voltage, and then I will take the line of best fit from which I will take the gradient and check whether the results I have obtained graphically matches the results in the table.

  2. Peer reviewed

    Investigation in resistance in wires

    5 star(s)

    Also the outliers on the longer wire lengths were more separated; I believe that this is because I didn't read either the ammeter or the voltmeter correctly The basic test of how reliable my experiment was is when I plotted the resistance graph, the further away from the origin the

  1. Physics GCSE Coursework:Factors affecting the resistance of a wire

    When an electric current passes through thin nichrome or tungsten wire, the electrons cannot flow easily. They collide with the atoms in the wire, which vibrate more quickly. This causes the wire to warm up. If the resistance of the wire is high and the current is large, the wire may get red hot.

  2. The resistance of wire.

    the same, The edge of the crocodile clips should be at the edges measured length. The Variable factor The factor that I am going to vary is the length of the E26 wire. Circuit diagram Method The circuit was set up as shown above.

  1. Length vs Resistance

    This means that resistance may be proportional to current. Though my values are definitely not accurate, since the increases are all different percentages, they are very reliable as the range between them is 4, which is small. To prove this hypothesis, I will also take figure from my graph, using my line of best fit and then I will

  2. Discover the factors affecting resistance in a conductor.

    This needs to be accurate, since it is a very important factor to ensure reliability. Secondly we need to state what we need to keep constant throughout the experiment. These are listed below :- * The diameter of the material This has an effect on resistance, so will need to be kept constant throughout.

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

    source of data matched my predicted data well because those predicted results were perfectly accurate. I know that my result were not perfectly accurate because of the heating affect and I have one a graph of standard deviation to sow how they differed and I know that this was down to the heating affect.

  2. Factors Affecting the Resistance of a wire.

    If the conductor is twice as large there will be twice as many collisions and hence the resistance of the conductor will be doubled (for constant cross sectional area). * Cross-section area (A) A conductor with a larger surface area has a greater number of conduction electrons, as it has a larger volume.

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