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

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

Extracts from this document...

Introduction

PHYSICS COURSEWORK

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

 For me to investigate this I must first use my scientific knowledge to understand exactly how and why the length of a wire should affect the current flowing through it. From this I will then be able to devise a suitable test.

Scientific Knowledge

Electric current- is the flow of electrons round a circuit. The current is produced from moving electrons, which are free to move around the circuit. They flow opposite to conventional current which, means they travel from negative to positive. Current is measured in Amperes (A).

Electrons can only move from the negative terminal of a battery to the positive end if there is an electric path between them. Materials that allow electrons to move through them easily, to form an electric current, are called conductors. These are mainly metals such as copper, gold and silver and also carbon (non-metal). Materials that do not allow electrons to move through them easily are called insulators. The wire going to be used is a metal and so this is why a current will pass through.

 Anything that slows the electrons down, by the atoms of the material resisting the flow, is a source of electrical resistance. All materials oppose current passing through them. It is this opposition that is the resistance.

...read more.

Middle

2.73

The results of the amount of current proved to not show enough range between the results and so would not give an accurate and reliable answer, after analysis, to either prove or disprove the prediction. It was therefore evident that I would have to change the resistance of the variable resistor to create more resistance to hopefully give a better range to the current results. This would make the data easier to analysis.

 The same test was repeated three times so that an average of the three tests could be calculated creating fairer and more reliable results that would, hopefully, give constant results.

Results of 3 tests

TEST 1

Length (cm)image15.png

Current (A)

Voltage (V)

0

-0.92

0.04

5

-0.85

0.52

15

-0.71

1.48

25

-0.61

2.15

35

-0.54

2.64

45

-0.48

3.04

55

-0.44

3.35

65

-0.40

3.64

75

-0.37

3.87

85

-0.34

4.05

95

-0.32

4.21

TEST 2

image14.png

Length (cm)

Current (A)

Voltage (V)

0

-0.92

0.03

5

-0.85

0.55

15

-0.70

1.53

25

-0.61

2.23

35

-0.54

2.72

45

-0.49

3.10

55

-0.44

3.40

65

-0.40

3.68

75

-0.37

3.89

85

-0.34

4.06

95

-0.32

4.20

TEST 3

image14.png

Length (cm)

Current (A)

Voltage (V)

0

-.090

0.10

5

-0.85

0.52

15

-0.71

1.51

25

-0.61

2.14

35

-0.54

2.68

45

-0.48

3.07

55

-0.44

3.41

65

-0.41

3.67

75

-0.37

3.89

85

-0.35

4.15

95

-0.32

4.25

The current ranges were 0.6.

...read more.

Conclusion

Evaluation

I feel that I have performed this investigation to my best capability and I believe that I have made a fair and valid conclusion.

 However, there were some odd results shown in my graphs and tables, although all the currents has a range of 6 so the results were not too obscure which means I still believe that my results are valid. These were probably due human error on my behalf or matters beyond my control.

 I believe that my experiment was suitable as it clearly showed a good conclusion, it was not hard to follow and formed a good basis for my investigation. Yet there are ways in which my experiment could be improved to overcome any errors that occurred such as; I could use a baby thermometer to check the heat of the wire to see if it was hot so that I could see where to end the experiment. I would end the experiment where heat was being produced, as at this time Ohm’s Law would mean that the experiment wasn’t working anymore and the results were becoming invalid. I could also repeat the experiment further so as to gain a mean from more results meaning fewer occurrences of errors in the findings. Also, if I was to use a higher resistance on the variable resistor it would mean less current and so less heat would be produced meaning more consistent and valid results

 To expand on this investigation I could experiment with different lengths of wire, wires of different materials and different temperatures as we used room temperature

SALLY DWIAR

...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. Finding a material's specific heat capacity

    Also, copper was chosen as it has a relatively low heat capacity. This is because it is a solid at room temperature and has a high density. The metallic copper atoms are closely packed and, when heated, begin to vibrate vigorously.

  2. Factors Affecting the Current Flowing

    The factor that I am investigating is Length and this will be the independent variable. The length of the wire has a great effect on the current that can flow through a metal conductor. I predict that the shorter wire will allow the most current through and the longer wire will allow the least current through.

  1. Free essay

    How can you change the level of current flowing in a metal wire?

    I have chosen the length because I can be very accurate with the length of the wire and use a wide range of lengths to test the resistance of the wire. Method * I am going to measure the length of the wire using the same ruler so I always get an accurate length.

  2. To investigate how the length of wire in a current affects the flow of ...

    If there is more resistance then the current will be lower and this will give me different results. Numbering and range The suitable voltage For the voltage I will use two volts, as I believe this is the best voltage in this investigation.

  1. Construct and test an anemometer.

    I then placed the anemometer with the motor attached to a multimeter into the wind stream. I then adjusted the position of the anemometer in relation to the wind source to achieve a constant potential difference created by the motor.

  2. Molecular stability (rheology) of a plastic carrier bag through stress - strain tests.

    1.7.1 High-density polyethylene (HDPE) A linear polymer is the most basic form of polymer structures (HDPE) HDPE has generally no branched chains. This allows molecules to 'attach' nearer to the molecule in a normal way, which is almost crystalline. This signifies that the dispersion forces are more effectual therefore the

  1. Current flowing in a wire

    Therefore the current will be lower if the voltage remains constant. I also predict that the thicker the cross sectional area of the wire, the less resistance the wire will offer will offer due to the availability of more space for the electrons to pass through.

  2. How the length of wire affects the current flowing through it

    I will attach each piece of wire, in turn, to the crocodile-clip leads and set the voltage to 0.4 Volts.

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