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

Factors Affecting the Current Flowing

Extracts from this document...


Factors Affecting the Current Flowing

Through A Metallic Conductor


An atom consists of a positively-charged nucleus with negatively-charged electrons moving around it. Charge is measured in Coulombs and the charge on an electron is 1.6 x 10-19C. Most atoms have an equal number of positive and negative charges; therefore the overall charge is zero. However, in some atoms it is easy to remove an electron, leaving an atom with an unbalanced number of positive charges. This is called a positive ion.


When a battery is connected across the ends of the metal, the free electrons move towards the positive terminal of the battery which produces an electric current. When a metal atom gives away a free electron which has a charge of 1.6 x 10-19C, it gains a positive charge. The free electrons move amongst the positive ions, whereas the positive ions can only vibrate about their fixed positions. The free electron is a current carrier; for an electric of 1 ampere, 1 coulomb of electric charge moves every second.


The Current in Amperes can be calculated using the following equation:

       Q                                        Where Q = Electric Charge

I = ──                                                    I = Current

        t                                              and t = Time

There are many factors that affect the amount of current flowing through a metallic conductor:

  • Length of wire
  • Thickness of wire
  • Temperature of wire
  • Voltage
  • Material of wire

All solids are made up of atoms that constantly vibrate about their positions. The higher the temperature, the greater the vibration. Electric current is the flow of free electrons through the material. As the electrons move, they collide with the vibrating atoms, so their movement is hampered.

...read more.



I found that the problem with these results were the fact that the current was too high and I feel the reason for this was that the voltage, at 1.20V was too high. However I had a problem, 1.20V was the only voltage I could find where I could get a current reading for both extremes. The only way I could think of, of reducing the voltage was to add in another variable resistor image04.png


A metal consists of ions (metal cations) surrounded by electrons. These electrons are free to move through the structure of the metal. When there is no applied external electric field, the electrons move randomly. When an electric field is applied, however, the electrons will be attracted towards the more positive potential and the cations towards the more negative potential. It is only the electrons which are free to move, these travel towards the positive potential. The electrons are accelerated towards the positive potential and their kinetic energy increases. But as they move through the metal they collide with the metal ions, this has the effect of slowing the electrons down and transferring some of the electron’s energy to the metal. In addition to slowing the electrons down, energy is transferred to the metal and this acts to heat up the metal. As the metal gets hotter and hotter, the metal ions vibrate more and more and so the number of collisions between ions and electrons increase, in effect the resistance to current flow increases.

...read more.


My conclusion is a very limited one, it is only suitable a wire of length up to 90cm. This conclusion may not necessarily be the same for other lengths of wire. Also the results are only for one type of wire. The results and therefore the conclusion would be different for another type of wire as it may conduct better resulting in a larger current. The results are at a constant voltage of 1 volt. If the voltage was higher there would be a larger current as the electrons would be provided with more energy giving them more of a chance of passing through the wire. The cross sectional area of the wire was also the same in all the wires, this means that the conclusion that I have reached is only suitable for a nickel-chrome wire of cross sectional area 30 with a voltage supply of 1 volt.

To expand on my conclusion, I could expand on the experimental procedure. I could use the same experiment on different wire cross sectional areas and different voltages to see if they gave me a similar conclusion. I could also experiment with wires mad of different materials to see if my conclusion related to any other material of wire.

...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)

    * I then Put all results into a table, calculating resistance and checking all calculations to make sure no mistakes had been made * I used a digital ammeter and voltmeter therefore I did not have to take parallax and zero errors into consideration.

  2. Discover the factors affecting resistance in a conductor.

    Therefore one of the factors of resistance is that as the length increases, so does the resistance. Therefore the resistance will decrease as I shorten the length of the putty, and as long as the cross-sectional area remains constant throughout the putty and the temperature remains constant, there will be a decrease that will be directly proportional to the length.

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

    I have decided not to investigate type of material since there are not a sufficient number of materials for me to investigate how this factor affects the resistance of a wire. Another disadvantage of investigating type of material is that it does not provide continuous data, consequently, not giving a good line graph.

  2. Factors affecting Resistance of a wire

    The reason that the copper wire had a very low resistance is due to a large amount of loose, or free electrons in the wire. These electrons are more easily able to carry electricity, therefore needing less push (provided by the voltage)

  1. relationship between voltage and current

    to a table and work out the Resistance using the rearranged formulae; R=V/I * Plot the values of the Current (I) against values of voltage (V) on a graph, this will then tell you the relationship, if its proportional the equation of the line will be Y=X but since this

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

    Another reason why a longer wire has a greater resistance is because the electrons have a greater distance to travel. This factor causes more resistance than the fact that a barrier is formed which blocks the way for electrons to flow more freely.

  1. Factors Affecting the Efficiency of a Wind Turbine

    other remaining experiments, so neither the list of apparatus nor the diagram showing the arrangement on the next page will be mentioned again throughout the project. The equipment that will be used: * Dynamo (acting as a wind turbine) * Hair Dryer (generating an artificial wind)

  2. Free essay

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

    * Then I'm going to apply the current. I'm going to use the same equipment to make the experiment fair. * Then I am going to wait until the ammeter shows a stable result then record this measurement. * I'm going to repeat this for each measurement three times then work out the average.

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