• 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

Factors affecting Resistance.

Extracts from this document...

Introduction

Factors affecting Resistance

Plan:

     The Task of this investigation is to find out the factors that affect the resistance of a wire.

This will be done by performing experiments that try and investigate different proposed factors and to see whether they affect the resistance.

Resistance is the force, which opposes the flow of an electric current around a circuit so that energy is required to push the charged particles around the circuit. Resistance is measured in ohms. A resistor has the resistance of one ohm if a voltage of one volt is requires to push the current of one amp through it.
Resistance occurs when the electrons travelling along the wire collide with the atoms of the wire.
These collisions slow down the flow of electrons causing resistance. Resistance is a measure of how hard it is to move the electrons through the wire.
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 directly proportional to the resistance increase.      

This tells me that the voltage measures the amount of energy used up in getting each coulomb of charge through the wire. The units of volts are the same as joules per coulomb. Therefore, Ohms law says the more resistance means more energy used to pass through the wire. Resistance is a measure of how much energy is needed to push the current through something.

...read more.

Middle

2

10

0.7

0.2

2.9

15

0.7

0.2

3.5

20

0.8

0.15

5.3

25

0.85

0.1

8.5

30

0.875

0.1

8.75

35

0.9

0.1

9

40

0.9

0.1

9

45

0.9

0.1

9

50

0.9

0.1

9

55

0.9

0.1

9

60

0.9

0.1

9

65

0.9

0.07

12

70

0.9

0.075

12

75

0.9

0.07

12

80

0.9

0.075

12

85

0.9

0.07

12

90

0.9

0.075

12

95

0.9

0.07

12

100

Observation

The results from my experiment, does have a relationship with the length of the wire, but its not necessarily in direct proportion to the length of the wire.

For example: Between 5-40cm of wire, the resistance is about what I expected, it is always increasing because the longer the wire the more atoms and so the more likely the electrons are going to collide with the atoms.

Between 40-65cm of wire, the resistance stays at a constant 9 ohms. And between 70-100cm of wire it has a resistance of 12 ohms. This could be because only 12v was travelling through the wire and therefore wasn’t powerful enough to change the resistance after a certain point. One thing, which is unknown, is the resistance goes up to 9 ohms and suddenly jumps to 12 ohms. This could be because of inaccurate results as the experiment was only taken once.

Analysis:

        Through my experiment and observations. I have found out that the resistance isn’t to direct proportion to the length of the wire, because this would mean, 30cm of wire = resistance of 8.5 ohms. So 60cm of wire would = resistance of 17ohms.

...read more.

Conclusion

Apparatus for future experiments:

  • Digital Voltmeter, and Ammeter. This would give very accurate results
  • Selection of wire, thicker wire with a higher voltage going into the wire, may give an more accurate result.
  • Higher voltage power pack, on my graph I found that my prediction seemed to be correct at the beginning, but went out of the proportion later on. I think this could have something to do with the voltage, as it’s responsible for the resistance in the first place. A power pack, which goes up to 30 volts, would be good.

Supporting my conclusion:

        I have said this under the Analysis, but here it is again. I think that my results could be suitable to confirm my prediction and support a conclusion. However, the results I would have to double-check, as it doesn’t match my prediction. I know that my prediction is correct because outside resources (Textbooks and Britannica) say that ‘the length increases in direct proportion to the resistance. ´

The experiment is repeatable, by using the method, but factors like temperature, length of wire, Diameter or thickness, and the type of metal affect the resistance so these factors have to remain constant throughout the next experiment.


By Alex Barber 10RA

...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

    The factors affecting the resistance of a metalic conductor.

    4 star(s)

    - 0.8 = 0.22/0.2 = 1.1 Therefore; R = 1/1.1 = 0.9 Below is my observation table that compares the value of R from my tabular calculations and the value of R from my graphical results: Area [m ] Calculated value of R [] Graphical value of R [] R

  2. Resistance of a Wire Investigation

    readings over a longer period, therefore increasing the volumes, and in turn reducing the percentage errors. Another error would have been due to background light in the vicinity. We tried to reduce this error by closing all blinds in the laboratory, but due to practical reasons, we could not all

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

    In this diagram the wire is half the length of the wire below and so has half the number of atoms, this means that the electrons will collide with the atoms half the amount of times. Also if the length of the wire was trebled or quadrupled then the resistance would also treble or quadruple, and so on.

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

    The electrons colliding into metal ions causes' resistance. So if the cross sectional area of a wire is doubled, the electrons won't have to squeeze together as much to pass through the wire so the electrons have half the chance of colliding into the metal ions so the resistance is halved.

  1. Discover the factors affecting resistance in a conductor.

    A Power Unit: I concluded that a power unit would be the safest and most simplistic choice to use in this investigation. If two battery packs were used it would result in a lot more wiring, and much more space taken up as a result, which would mean a crowded working area.

  2. An investigation into the factors affecting the resistance of a wire.

    I can now work out the resistance using the current and Voltage: R=V/I (ohms law) R - resistance in ohms (?? ohms) V - voltage (volts) I - current (amperes) I have discovered the circuit itself can resist the flow of particles if the wires are either very thin or very long.

  1. The aim of this investigation is to investigate the factors affecting the resistance of ...

    Resistivity is a fundamental characteristic of the material itself defined by the voltage divided by the density of current (current per unit cross-sectional area) flowing across the material. A material of high resistivity will require a higher electrical field to cause a given current density.

  2. To investigate how the length (mm) and the cross-sectional (mm2) area of a wire ...

    Overall, I believe that I obtained enough results to come to a conclusion about the relationship governing the two variables. Even though I could repeat my experiment several more times, it would be irrelevant to the experiment since I have already formed a conclusion regarding length and resistance, which supports my hypothesis and is supported by scientific knowledge.

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