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

What determines the resistance of a metallic conductor? Investigate a physical factor that will affect resistance of a piece of Constantan/Nichrome wire.

Extracts from this document...


GCSE Physics Investigation                                          


What determines the resistance of a metallic conductor? Investigate a physical factor that will affect resistance of a piece of Constantan/Nichrome wire.

Possible Variables to be investigated:

Current, Temperature of wire, Length of wire and thickness of wire

Independent Variables:

 This is the variable that I will change. It will be the length of wire.

Dependant Variable:

This is the variable that I will measure. This will be voltage so I can work out the resistance using ohm’s law equation, Voltage (V) = Current (I) x Resistance(R) I will rearrange this equation to Resistance (R) = Voltage (V) / Current (I)

Controlled Variables:

These are the variables that will stay the same. They are Current, Temperature of wire and thickness of wire.

Background Knowledge:

                                                                                                                                        Resistance is a 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. The circuit itself can resist the flow of particles if the wires are either very thin or very long. E.g. the filament across an electric bulb is quite thin as needs to resist the flow of particles for the bulb to glow.
Resistance is measured in ohms.

George Ohm discovered that the emf of a circuit is directly proportional to the current flowing through the circuit.

...read more.


Predicted graph:

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 power pack is switched on, because the current would heat up the wire.

Diagram of Apparatus:

                                                                                                                                     Voltmeter                                                                                                                       Power pack
Nichrome wire
Meter Ruler                                                                                                             Crocodile Clips
Connection Leads

I set up my experiment as shown above.

I started the experiment by attaching the Nichrome Wire (over 80cm long) to the meter ruler then cut to size. Then the power pack was switched on which was connected to the Nichrome wire via the crocodile clips. The resistance was then recorded down for various lengths ranging from 20cm to 80cm. I recorded each in a table.

To collect the data for my graph I had chosen to take a range of 7 lengths. I had chosen a range of 7 as to plot an accurate graph I will need at least 7 points to mark on the graph.

...read more.


C = A - B

A = overall resistance of Nichrome wire, crocodile clips and connecting leads
B = overall resistance of crocodile clips and connecting leads
C= resistance of Nichrome wire
I also found that the experiment was quite easy to set up, as it was simple and uncomplicated.

Further experiments I could do related to the resistance in a wire, would be to see whether the following factors would make a difference in the resistance of a wire: (I have made a prediction for each factor from my own scientific knowledge on how I think the resistance would change in a wire for that particular factor)

 Wire width:

I think that if the wire width is increased the resistance will decrease. 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.


I think that if the wire is heated up the atoms in the wire will start to vibrate because of their increase in energy. This causes more collisions between the electrons and the atoms as the atoms are moving into the path of the electrons. This increase in collisions means that there will be an increase in resistance.

Stuart Mc Gaffin

...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)

    The above-mentioned results occur due to the fact of how many free electrons are being conducted through the wires of different lengths and areas. * In the case of length; the resistance increases as the length increases because a wire with a shorter distance will have a smaller amount of atoms for the free electrons to hit.

  2. Marked by a teacher

    Resistance Aim: my main aim is to investigate the factors that affect the resistance ...

    3 star(s)

    across the ends of a conductor (R) to the current (I) flowing in that conductor will also be constant." Or... the current passing through a wire at constant temperature is proportional to the potential difference between its ends. From this, we conclude that: voltage divided by resistance ( I=V/R ),

  1. Length vs Resistance

    There was also some resistance in the other components, for example the connecting wires, the ammeter and the voltmeter. They provide resistance as the electrical current has to flow through all of them, though the resistance may not be of a very large amount.

  2. Discover the factors affecting resistance in a conductor.

    Below is a sketch to show what my graph should look like. As you can see, the smaller diameters show a higher resistance, so the gradients will be steeper. Therefore, it is predicated that the resistance is proportional to the length, but inversely proportional to the diameter.

  1. How does length and width affect resistance

    Width of wire: The width of a wire will affect the resistance because the wider a wire the more space in the net for the charged electrons to get through without colliding with the net and therefore decreasing the resistance.

  2. An experiment to find the resistivity of nichrome

    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 proportional to the resistance increase. 4.Wire width : If the wires width is increased the resistance will decrease.

  1. Factors which affect the resistance of a wire

    In order to make my results as accurate as possible I will straighten out the wire when I cut it so the length will be accurate. I will also take readings from my practical experiment three times and average out the average resistance of the wire so that it reflects on the most accurate result.

  2. Investigate the factors That Affect the Flow of Electricity Through a Conductor.

    Consequently, the resistance of as substance causes the current to decrease, as the charge flows slower, because there is a decrease in kinetic energy, as collisions constantly make them slow down. Therefore the greater the resistance the smaller the current.

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