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

The Factors Affecting The Resistance Of A Wire

Extracts from this document...

Introduction

Samir Khan 4S2        Factors Affecting Resistance Of A Wire

Mr. Kerr

The Factors Affecting The Resistance Of A Wire

Plan

Aim: - The aim of this investigation is to investigate what effects different factors have on the resistance of a wire.The investigation will determine what effects the factor we choose has on the resistance of a wire.  

Variables and Key Variables: - There are many possible independent variables that could be changed in order to affect the dependant variable.  The dependant variable in this experiment is that of resistance.  This means that resistance will not be changed or controlled during the resistance but the independent variable will be used to change it.  I came up with many initial ideas for things that could be used as the dependant variable in my investigation.  These include: -

  • Length
  • Width- Diameter/Cross-Section
  • Current
  • Voltage
  • Temperature
  • Material
  • Room Temperature
  • Age Of Wire
  • Humidity
  • Light
  • Pressure
  • Magnetism

Preliminary Work: - In order to find out the best variable to investigate with regard to what affect it has on resistance a number of preliminary tests had to be carried out.  The aim of these small-scale experiments was to see which of the possible dependant variables have an effect and then to find out which of them would be best to investigate.  Some possible variables had to be ruled out from the start.

...read more.

Middle

: - The next decision I was required to make was to select the best wire to use for my investigation out of those available.  In order to find this I had to experiment using different wires in order to see which one with which thickness is the best to use.  For the first part, in order to find out which thickness to use, I decided to select a wire to use.  I decided to use Constantan simply because it had the greatest range of wires.  I decided to observe the resistances of the same material of wire using different thickness.  This was done by connecting the wire to an ohmmeter and observing the resistances.  The wire was connected using crocodile clips and the length of these crocodile clips apart from each other was how I measured the length.  A metre rule was placed next to it in order to ensure accuracy.

Diameter 0.914cm

Length (cm)

Resistance

10

1.3

50

1

90

0.7

Diameter 0.152cm

Length (cm)

Resistance

10

2.6

50

13

90

24.5

From these results in the preliminary experiment it is obvious that the greater the width the greater the resistance and therefore the greater the range of resistances in our results.  Therefore from this experiment I conclude that I decided to use diameter 0.152cm for the main investigation.

...read more.

Conclusion

I will now explain scientifically why certain variables must be kept the same throughout the investigation.  The temperature must be kept the same as when you raise the temperature more atoms vibrate and this impedes the passage of free electrons.  Thickness of the wire must be kept the same as if you vary this you also vary the amount of room electrons have to manoeuvre.  Finally the current must also be kept constant because as this increases so does the temperature of the wire.  All these precautions must be taken in order to ensure that the data obtained is as accurate as possible as well as being reliable.

...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)

    1/R = 1/R1 + 1/R2 In relation to the cross sectional area of the wire this would be calculated as: Since area is inversely proportional to resistance, 1/A = 1/A1 + 1/A2 which would be equal to, 1/R = 1/R1 + 1/R2 Owing to the fact that the circuit is

  2. Marked by a teacher

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

    3 star(s)

    y/x = 40.68/0.20 = 203.4 Resistance = 1/203.4 = 0.00491 x 1000 = 4.91 0.32mm Gradient = y/x = 22.60/0.20 = 113 Resistance = 1/113 = 0.00884 x 1000 = 8.84 Series Material: Nichrome Wire Length: 100cm and 75cm Thickness: 0.45mm mA Resistance (?)

  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. Discover the factors affecting resistance in a conductor.

    A diode has a resistance that is only large one way; the other way it is very small. It conducts in one direction only and is a non-ohmic conductor. "GCSE Physics" by Tom Duncan, states that "this makes it useful as a rectifier for changing alternating current (a.c.)

  1. Factors Affecting the Efficiency of a Wind Turbine

    The equation used in this case is 1/2mv2 = 3/2 KT where K is constant, T is temperature in Kelvin and v is velocity of wind. M represents the mass. Sources of error The main source of error in this particular experiment is the way temperature was measured.

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

    Because the resistance is very high which in effect causes some heat to be dissipated. I actually felt some heat after switching off the power pack. So in my real experiment I will use 32 SWG Nickel Chrome. Power Dissipation = V^ R When V is kept constant, the power dissipated decreases as the resistance increases.

  1. Investigating the factors affecting the resistance in a wire

    As there were no ohmmeters available to measure the resistance, we recorded the current in the circuit using the ammeter and the potential difference across the test wire using the voltmeter and used Ohm's Law to calculate the resistance by dividing the potential difference by the current.

  2. Free essay

    Factors Affecting the Resistance of Wire.

    To ensure as accurate results as possible I worked in a pair, so that whenever we had to change something or read the voltmeter ourselves the other person could double check we had done it correctly. We also used a low current at 0.2 amps, we did this so that

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