• 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

In this investigation we are going to investigate the factors affecting the resistance of nichrome wire in an electric circuit

Extracts from this document...

Introduction

Physics investigation

Introduction

In this investigation we are going to investigate the factors affecting the resistance of nichrome wire in an electric circuit

Background Knowledge

The first requirement for conduction is a supply of charge carriers that can move freely through the material. In most solid conductors, notably metals, these carriers are thought to be loosely held electrons. For example, copper has one electron for every atom. The free electrons in a solid conductor are in a state of rapid motion, moving within the crystal lattice at speeds calculated to be around 1/1000 of the speed of light. This motion is normally haphazard (like that of gas molecules) and as many electrons with a given speed move in one direction with the same as in the opposite direction with the same speed. There is therefore no net flow of charge and so no current.

If a battery is connected across the ends of the conductor, an electric field is created in the conductor, which causes the electrons to accelerate and gain kinetic energy. Collisions occur between the accelerating electrons and atoms (really positive ions) of the conductor that are vibrating about their mean position in the crystal lattice but are not free to undergo translational motion. As a result the electrons lose kinetic energy and slow down whilst the ions gain vibrational energy

Electrons move round and round the nucleus in paths called orbits.

...read more.

Middle

Independent Variable

Dependent Variable

Controlled Variable

I am going to change the length of wire during this experiment.

I am going to measure the resistance of the wire by using ohm’s law.

current that we pass through the wire.

material of the wire.

cross sectional area of the wire.

Same room temperature.

Same wire used for every test.


Prediction
I predict that if the width increases then the resistance will also increase in proportion to the width. I think this because the thicker the wire the more atoms and so the more likely the electrons are going to collide with the atoms. So if the width is doubled the resistance should also double. This is because if the width is doubled the number of atoms will also double resulting in twice the number of collisions slowing the electrons down and increasing the resistance. My graph should show that the width is proportional to the resistance.
Because the width of the wire is only half the width of the wire below there should be half the number of collisions between the electrons and the atoms. The wire below is twice the width of the wire above and so there should be twice the number of atoms resulting in twice as many collisions and a predicted doubling of the resistance.

List of the apparatus

  • Power pack supply of up to 12V
  • A full scale deflection ammeter with a measuring range of 0-1
  • A voltmeter with a measuring range of 0-5 V
  • Circuit wires
  • Nichrome wire 0.35m in length
  • A meter ruler
  • Crocodile clips
  • Switch
  • Pencil
...read more.

Conclusion

ass="c3">1.8

1.67

15

3

1.25

1.2

1.25

1.23

2.44

20

3

1.00

1.0

1.00

1.00

3

25

3

0.69

0.69

0.69

0.69

4.35

30

3

0.57

0.58

0.58

0.58

5.17

35

3

0.49

0.48

0.49

0.49

6.12

40

3

0.43

0.42

0.41

0.42

7.14

45

3

0.38

0.38

0.39

0.38

7.89

50

3

0.34

0.34

0.34

0.34

8.82


Safety Precautions

There are not many safety precautions that need to be taken into consideration, in this experiment. The main two I can think of are stated below :

  • Do not carry out the experiment in wet areas, as water is a very good conductor, and thus could be very dangerous.
  • Do not touch the wire when the circuit switched on, because the current would heat up the wire and it may be extremely hot.
  • Keep the voltage at a lowish level so as no-one will be electrocuted

...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)

    Each time noting down the corresponding ammeter readings. I do this to make sure the readings of the ammeter while increasing and decreasing the voltage are the same almost with a slight variation, therefore making sure that no heating has taken place. I will then note down the ammeter readings while decreasing the voltage in steps of 0.50

  2. An experiment to find the resistivity of nichrome

    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 less collisions. To chose which factor I am going to investigate I am going to consider how I would measure each factor and which factor would be the best and easiest to record.

  1. Factors Affecting the Efficiency of a Wind Turbine

    * Reading an oscilloscope's manual instructions before using it. This allowed me to connect all leads on the correct place. Accuracy of instruments 1) Wind gauge measured to two significant figures and zero decimal place. Therefore not accurate and less sensitive but it was the only one available so I had no choice.

  2. To investigate the factors affecting current in a wire.

    I must also keep the surrounding room temperature the same or the particles in the wire will move faster (if the temperature is increased) and this will therefore have an effect on the resistance. To keep the cross-sectional area of the wire constant, I will note down the SWG of the wire I'm using.

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

    I will take 3 readings for each current and voltage, and I will work out averages and resistances as I did in the 1st experiment in which we tested for how the length affects the resistance. I am using the following cross-sectional areas: 0.01824 cm�, 0.04301 cm�, 0.1104 cm�, and 0.16403 cm�.

  2. The Efficiency of an Electric Motor.

    This graph will allow me to correct for errors caused by the inaccuracy of the joule meter when I analyse my results. I have not had enough time to calibrate the joule meter using a wide range of voltages and energies and therefore my calibration curve is not as useful as it could have been.

  1. Resistance of a Wire Investigation

    Take the reading from the ammeter recording both the current and the voltage. Then do the same again but use voltages of 0.2 volts, 0.3 volts, 0.4 volts, and 0.5 volts. This is so that when we work out the resistance (V/I)

  2. Investigate one or more factors affecting the resistance of metal wires

    This will ensure that I obtain precise and accurate evidence. Obtaining Evidence The resistance was calculated using each of the values of voltage and current using the formula: R = V/I The cross-sectional area was calculated using the formula: A = ?d� /4 As you will see, my repeated current

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