• 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

Investigating the Physical Factors that affect the Resistance of a Wire.

Extracts from this document...

Introduction

Investigating the Physical Factors that affect the Resistance of a Wire

Introduction

An electric current in a wire is a flow of charge due to electrons moving along the wire. Electric current is measured in amperes (A).

The potential difference (p.d.) between two points in a circuit is the electrical energy converted into other forms of energy when one coulomb of charge passes from one point to the other. The potential difference unit is the Volt (V). It is also known as voltage.

        When the same potential difference is applied across different conductors, different currents flow. Some conductors offer more opposition or resistance to the passage of current than others do.

The resistance, R, of a conductor is defined as the ratio of the potential difference (V) across it, to the current (I) flowing through it:

Resistance = Potential Difference

Current

Resistance is measured in Ohms (Ω). One Ohm is the resistance of a conductor in which the potential difference applied across it is 1 Volt, and in which 1 Ampere of current is maintained. A wire has resistance because when the current flows through the wire, the electrons move along. As they are moving, the metal atoms obstruct the flow of electrons, slowing the flow down. this is resistance.

...read more.

Middle

(V)

Resistance

(Ω)

Range of resistance

(Ω)

Constantan 22swg, 10cm

0.4

0.0

0.00

0.50

Constantan 22swg, 30cm

0.4

0.2

0.50

Constantan

34swg, 10cm

0.4

0.4

1.00

2.25

Constantan

34swg, 30cm

0.4

1.3

3.25

Manganin 28swg, 10cm

0.4

0.2

0.50

0.75

Manganin

28swg, 30cm

0.4

0.5

1.25

Manganin

30swg, 10cm

0.4

0.2

0.50

0.75

Manganin

30swg, 30cm

0.4

0.5

1.25

Nichrome

22swg, 10cm

0.4

0.1

0.25

0.00

Nichrome

22swg, 30cm

0.4

0.1

0.25

Nichrome

32swg, 10cm

0.4

0.6

1.50

3.50

Nichrome

32swg, 30cm

0.4

2.0

5.00

Conclusion

As the results show, Nichrome 32swg had the highest range of resistance from 30cm to 10cm. For the main investigation, I will investigate how the length of a wire (Nichrome 32swg) affects its resistance. I am going to use 32swg as this has the largest resistance range. As 32swg is the narrowest wire, we can also learn that the narrower or thinner the wire, the larger the resistance.

Fair test

  • The current was kept constant throughout the investigation to ensure that the results were not affected by a change in the amount of current supplied, and by the temperature of the wire.
  • Two lengths of wire were used, at 10cm and 30 cm, so a range of lengths could be used to make the results more accurate.
  • The temperature was kept the same, at room temperature, to ensure the final value for resistance was accurate and not affected by temperature.

Safety precautions

  • The power pack will be turned on and off as quickly as possible to prevent the wire from over heating.
  • The circuit will be connected up securely and will be checked before being used, as any lose flow of electrons could be dangerous.
  • When cutting the wire with the wire cutters, care will be taken to prevent being cut by the wire cutters.
...read more.

Conclusion

        There are different ways in which the method could be improved to make the whole experiment more accurate. In this investigation, only one factor was investigated however, other factors could have been investigated. Also, different types of material could have been tested to see if the theory: Resistance  Length remains true. Also, a more accurate or sensitive voltmeter could have been used to make the voltage readings more accurate. An ohmmeter could have been used as well as the method which we used, so that the two sets of readings could be compared. From this we could have seen how accurate the sets of results were. The resistance of the wire could have also been measured using the equation:

Resistance =    L

                                                       A

The results for that could have also been compared with the results obtained from the original investigation.

        Overall, I think that the investigation was carried out fairly and accurately and this can be seen by the results, which support the prediction and the theory that length is proportional to resistance.

BIBLIOGRAPHY

www.google.com

www.ai.it.edu

Microsoft Encarta 96 Encyclopaedia

GCSE Science Assessment Sc4

                

...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)

    This should merely involve testing different lengths of one type of wire. There is no range perimeter to how long the lengths could be but it is uncertain that they will surpass 1 meter. Wires with different diameters need to be tested to prove that the resistance of a wire is inversely proportional to its area.

  2. Resistance of a Wire Investigation

    My idea that the rate of photosynthesis would increase with light intensity was comprehensively backed up by my results. This is because a higher light intensity involves a greater level of light energy, which can then be transferred to a special protein environment designed to convert the energy.

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

    that by extending the investigation it would be best to investigate the how the cross sectional area of a wire affects the resistance. First by setting up the apparatus as shown below in the diagram. With the voltmeter parallel to the wire and the ammeter in series with the wire.

  2. Discover the factors affecting resistance in a conductor.

    We could easily tell which results were false, by working out the resistance as we went, allowing a break in the trend of results to be seen. These results could then be repeated, and the correct ones taken. If these had not been repeated, the overall results would have been less accurate, also effecting the graphs.

  1. An experiment to find the resistivity of nichrome

    During my experiment I have noticed several modifications I could make to improve on the Investigation if I was to repeat it. The first of these modifications would be the circuit that I would use. To be more accurate with my results I would use the circuit layout below: POWER

  2. Factors which affect the resistance of a wire

    To investigate how the thickness of a material affects the resistance of a wire I will need to calculate the resistance of wires with different gauges and compare the pattern in the resistance. I will then draw graphs for both of my experiments Method 1.

  1. Investigate the factors that affect the resistance of a wire.

    Diagram 1 Diagram 2 The resistance of an object all depends on what it is made of, by the temperature the object is at and the length and width of the object. At a given temperature (if constant), the resistance is proportional to the objects length, and inversely proportional to its cross sectional area.

  2. Investigation of the factors that affect the resistance of a wire.

    Furthermore, if the atoms in the material are closely packed then the electrons will have more frequent collisions and the resistance will increase. 3.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 are likely to occur.

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