• 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
  12. 12
    12

An investigation into how the resistance of wire is related to the length.

Extracts from this document...

Introduction


BACKGROUND INFORMATION

A circuit is a continuous path, which is composed of an electromotive force (a power supply/battery) to drive the current around the circuit and conductors and conducting devices to carry the current, in a full circuit.  In a circuit, the direction of flow is always from the positive side of the battery to the negative side (this is a conventional flow), but the electrons flow in the opposite direction as they are negative and so they are attracted to the positive side.  This is called a closed circuit.  A series circuit is where the current is passed through every device which is part of the circuit without branching off into parallel circuits.

Metals conduct electricity.  This is because of their structure – a regular lattice arrangement of charged ions which are surrounded by electrons.  Metals are good conductors of electricity because the electrons are free to move inside of the metal.  This is because the electrons can easily detach themselves from their atom.

image00.png

In an atom, the majority of the mass is contained in the nucleus.  The nucelus consists of protons and neutrons.

PARTICLE

MASS

CHARGE

proton

1

+1

neutron

1

0

electron

1/1870

-1

The electrons in the atom orbit the nucleus, similar to the planets orbiting the sun.image01.png

...read more.

Middle

2.3

0.1739

5

0.3

2.3

0.1304

10

0.2

2.4

0.0833

10

0.2

2.4

0.0833

10

0.2

2.4

0.0833

15

0.2

2.4

0.0833

15

0.2

2.4

0.0833

15

0.2

2.4

0.0833

CONCLUSION

These experiments did not work, as all of my results are roughly the same.  This is because the resistance was too low in the wire to see a noticeable change in the meter readings.  As nickel chrome is a fairly thick wire I have decided to proceed with the rest of my experiments using a wire which has a higher resistance, so a smaller cross sectional area.  The wire I chose was constantan wire.


HYPOTHESIS

I predict that when using a thinner wire I will obtain good results and that I will be able to show clearly the increase of resistance as I increase the length.  This will be because the amount of atoms in the wire has increased and so there will be more atoms to collide with the electrons.  

I think that when I plot a graph of unit length (cm) against resistance (ohms) it will show clearly that they are proportional to each other, as I think when the length of the wire is doubled, the resistance will be too. I think that the graph will look similar to:

image02.png

...read more.

Conclusion

5.1 - 5.23 = -0.13

-0.13/5.1 = -0.0255 (to 3 significant figures)

-0.0255 x 100 = -2.6% (to 1 decimal place)

These accuracy problems could be due to parallax error (I could have looked at the metres from different angles each time), temperature changes due to the wire getting heated or the variation in the contact made by the crocodile clips.

EVALUATION

I feel my overall results were accurate.  This is shown in my graph where the points I have plotted are touching or very near the line of best fit.  I did not have any anomalous results; the reliability of my results was increased because I conducted 3 experiments at each length.  

I found it quite difficult measuring the wire accurately.  This is because it was hard holding the wire straight while measuring it and then using the crocodile clips to secure the length.  I was not sure that the crocodile clips were very secure, but by looking at my graph I now think the lengths I measured were accurate and the connections secure enough.  

If I were to redo my experiments I would change the following factors: I would use pointers instead of crocodile clips, as they are more accurate because they have a smaller tip and they would not constrict the wire where they were attached to it.  I would also prefer it if the wire were completely straight before I start my experiments.


BIBLIOGRAPHY

Oxford Interactive Encyclopedia                        CD – ROM

AirCom Education                                        CD – ROM

Physics For All                                        Book

Radio Communication Handbook                        Book by RSGB

...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. Peer reviewed

    electomagnet lab

    3 star(s)

    turns, the induced magnetism becomes stronger as there is a longer length of wire and thus more electrons can flow through it. However, the relationship is not directly proportional because every turn will not induce the same magnetic force in the electromagnet.

  2. Electromagnet lab

    5. In a Petri dish, place some iron filings. It is not necessary to record their mass. 6. Connect the other end of the wire to another insulated wire using crocodile clips. 7. The insulated wire must be connected to the other terminal of the power pack.

  1. Resistance of a Wire Investigation

    This is backed up with knowledge from previous experiments and ones done by other people and scientific understanding. Diagram Previous experiment Method For our experiment we chose as accurate equipment as possible to give us the most accurate results.

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

    Current (A) Resistance V/I (?) 0.083 0.060 1.383 0.104 0.075 1.387 0.127 0.091 1.396 0.169 0.121 1.397 0.185 0.133 1.391 0.215 0.154 1.396 0.249 0.179 1.391 0.314 0.226 1.389 0.437 0.314 1.392 0.308 0.22 1.387 Total 1.391 E30 wire with the length at 15cm Voltage (V)

  1. Finding a material's specific heat capacity

    3450 20.4 13.0 4926 1935 2991 3480 20.3 13.0 4926 1935 2991 Turning points/anomalies: The first graph to follow shows how the temperature of the metal rises during and after heating and then begins to cool. This is because the heater is turned off and, as the copper's surroundings are colder, heat energy is dissipated.

  2. Resistance in a Wire Investigation

    and this will therefore have an effect on the resistance. The cross sectional area of the wire must be kept constant throughout as well. This is shown in equation (2) where the cross sectional area is a factor that effects the resistance.

  1. Choosing a light source

    wave The formula below is the general formula that can be rearranged to work out the wavelength of the light. Order of angular separation x wavelength (?) = distance between slits (d) x angle(sin ?) The formula can be rearranged to work out the wavelength of the light that passes through the diffraction grating.

  2. Investigate how the electrical resistance of a wire changes in relationship to it's length.

    of it, I decided to use the length of the wire as the variable. Aim The aim of my investigation is to investigate how length affects the resistance of a length of wire Resistance is the force, which opposes the flow of an electric current around a circuit so that

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