• 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
  13. 13
  14. 14
  15. 15
  16. 16

Resistance Coursework

Extracts from this document...




In this investigation I want to find out how the length of and the width of the wire affects the resistance.


An explanation of what resistance would be that resistance is the opposition of a                                    conductor to a flow of current. It is when traveling electrons in a wire collide with the atoms of a wire. The collisions between the electrons and the atoms cause the electrons to move slower, which causes resistance. So, resistance would be how hard it is to move electrons through a wire. Resistance is measured in Ohms (   )

                   Resistance =     resistivity p (ohm metres) x length l

                                          Cross-sectional area A (square meters)*

Current flows through a wire by a flow of electric charges.  Wire is made up of a lattice of positive ions, surrounded by 'free' electrons. Ions can only vibrate about in their fixed positions but electrons are free to move randomly from one ion to another. When the battery is attached to the wire, the free electrons are repelled by the negative and attracted to the positive. They still have some random movement but they move slowly in the same direction through the wire with a steady drift.

Ohm’s Law:

In 1827, a German physicist discovered relationship that the amount of steady current through a large number of materials is directly proportional to the potential difference, or voltage, across the materials. Thus, if the voltage V (in units of volts) between two ends of a wire made from one of these materials is tripled, the current I (amperes) also triples; and the quotient V/I remains constant. The quotient V/I for a given piece of material is called its resistance, R, measured in units named ohms.

...read more.


In metals, the outermost electrons are held only very weakly to the atom and often wander away from it and go to the nearby atom or one a bit further away. These wandering electrons are called conduction electrons and the more of these there are, for a given volume of metal, the better the metal will be as a conductor of electricity. When you connect a battery across a wire, one end becomes positive and attracts the conduction electrons, which drift towards that end of the wire. But the electrons have obstacles to face because the metal atoms are jiggling about because of their thermal energy and so the electrons collide with them and are knocked all over. It’s this difficulty that the electrons have in moving along the wire that we call resistance.

Resistance involves collisions of the current-carrying charged particles with fixed particles that make up the structure of the conductors. A resistor is a material that makes it hard for electrons to go through a circuit. Without resistance, the amount from even one volt would be infinite. Resistance occurs when electrons travelling along the wire collide with the atoms of the wire.

The unit of resistance is Ohms and the symbol is:

The higher the resistance, the lower the current. If there is high resistance, to get the same current a higher voltage will be needed to provide an extra push for the electricity.

Some metals have less resistance than others. Wires are always made out of copper because copper has a low resistance and therefore it is a good conductor. The length and width of a wire also has an effect.

A variable resistor alters the amount of current flowing easily, which makes it very useful for speed control or light dimming.

...read more.


I believed that my investigation and the results are mainly accurate because my investigation was carried out very well. I believe that if I had to use my results as evidence I think they show that the longer the nichrome wire the more resistance and the shorter the less. I assume this because my graph shows at 10cm of nichrome wire there is 0.592(ohms) and at 100cm of nichrome wire there is 2.386(ohms) there is a difference of 1.794(ohms) which proves longer the wire the more resistance. I can prove that my experiment was successful because of the graph I drew. It showed length of wire against resistance.  If I had to further improve my investigation I would carry it out again and I would do it with a much longer piece of wire at a higher current.

If I had to do this experiment again I will probably measure the wire every 5cm’s instead of 10cm’s to make sure it’s accurate and use a more accurate volt meter to get the best and accurate results. . I could also investigate how the diameter of a wire affects the resistance.

An extra investigation I can carry out or perform to receive more proof and evidence would be to investigate and look into is the thickness of a wire and evaluate or match up with the length of the wire. Also I could examine if the specific metal materials or properties makes a change in the resistance.

...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

    Ohm's Law coursework

    4 star(s)

    Voltage (V) Current (A) Resistance (W) (to 2 d.p.) 10 0.92 1.05 0.88 20 1.16 0.66 1.76 30 1.28 0.47 2.72 40 1.34 0.39 3.44 50 1.38 0.32 4.31 60 1.42 0.27 5.26 70 1.45 0.23 6.30 80 1.47 0.21 7.00 90 1.47 0.17 8.65 100 1.48 0.16 9.25 Averages

  2. Investigating how the resistance of Nichrome wire depends on its length

    As they move faster through the wire, there are collisions between the electrons and the positively charged ions of the wire and when the fast flowing electrons collide with the ions, it causes resistance. We can also predict this in a microscopic view.

  1. The resistance of a wire depends on certain factors. Some of these variables are ...

    Use the metre ruler to mark out 10cm intervals to 100cm 4. Measure the voltage in the voltmeter and the amps in the ammeter. 5. Record the readings. Calculate the resistance using R= V/I 6. Allow time for wire to cool down 7.

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

    These electrons find it easier to pass through some materials than other material. For example I know that nichrome wire has a higher resistance than a copper does because I know that electrons have to squeeze together more or collide with each other in order to be able to pass

  1. An experiment to find the resistivity of nichrome

    Apparatus: � Power Pack � Constatan wire � Leads � Voltmeter � Ammeter Method: 1. Arrange apparatus as shown in the Diagram: 2. Cut wires to the following lengths: � 30cm � 60cm � 90cm � 120cm � 150cm 3.

  2. Free essay

    Aim: the aim for this experiment is to check if the length of a ...

    * In bright light, the resistance of an LDR is low and more current can flow through it. Factors affecting Resistance: > Length of wire - the longer the wire the higher the resistance because in a long wire there are more metal ions for the electrons to pass through.

  1. An Investigation into how the Length of the wire affects its resistance

    * I am going to use the same apparatus and components throughout the experiment so if one particular component has a problem, the test will still be fair because each every part of the experiment will be done using the same apparatus.

  2. How the length of nichrome wire affects the resistance

    * Crocodile clips * Ruler * Resistance board * Variable resistor Diagram: Safety: I will not touch the wire until it

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