• 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

# This investigation discusses the aspects of wire resistance in a particular wire. I will be investigating the variable factors of wire resistance and setting up a simple circuit to test for wire resistance.

Extracts from this document...

Introduction

Resistance of Wire

Aim:        This investigation discusses the aspects of wire resistance in a particular wire. I will be investigating the variable factors of wire resistance and setting up a simple circuit to test for wire resistance.

Hypothesis:

Everything on Earth is made of tiny building blocks called atoms. Inside atoms are smaller electrically-charged moving particles called electrons. It is the movement of these electrons that creates electricity. Some substances - especially metals - have electrons which can flow freely from one atom to another. The flow of electrons from one atom to another is know as an electric current, this is measured in volts (V). Metals such as copper and aluminium are particularly good at allowing the free flow of electrons and are known as conductors. These two metals are the ones most commonly used in electrical wiring. Resistance is how much the electrons don’t move and is measured in amps (A). The electrons in metals like copper move very easily so they have a very low resistance. Constantan as another example has a higher resistance because electrons in its atoms do not move as easily. The following diagram explains how this works.

The flow of electricity can also be explained by the following diagram.

Electricity on an atomic level

The atomic number of copper is 29, which means it has 29 protons in the middle and 29 electrons moving around the outside.

Middle

•        Voltage applied (V)                                                         (Constant)

•        Temperature of wire                                                 (Constant)

I decided to use the length of the wire as the factor that I will change, this is because it will give the widest range of results.                                 I decided to test the resistance of wire using increments of 100mm of constantan. Constantan is an alloy metal made of copper and nickel. I will start at 100mm and go up to 1000mm on the same piece of wire to ensure a fair test and give a wide range of results.                         My reason for using constantan is that I already know it has a noticeable resistance. I know this from the research I did before conducting the experiment. It would not be a wise choice to use copper as the material of wire because copper has a low resistance therefore I would need to use very long pieces of wire before a noticeable change in resistance was visible.                                                                         The thickness of wire, or SWG, I will be using is 28 SWG. This is 0.375mm thick and should be the most suitable for this experiment.                The voltage I will be applying is 1 volt, according to the power pack. During the preliminary experiment the volt meter recorded a voltage of about 1.5 volts. If a too high voltage is applied then the wire will become very hot and affecting the resistance of the wire, using a too low voltage will not give accurate results.

Conclusion

Evaluation

From my results I now know how I could have made it better and more accurate. To begin with I made the right decision to use digital meters. I chose digital not analogue so I could record exact results, rather than guessing the reading from a needle.

I chose a wooden ruler to measure with so I could be sure it would not short the circuit, meaning it would not make any connections between the wire and the ruler.

I didn’t however make the right choice of using crocodile clips to connect to the wire. The width of a crocodile clip is about 3mm, so when connecting it to the wire it could easily make results incorrect. The crocodile clip could be 3mm either way of each measurement. If some one was measuring it at 100mm it could be possible that the clip was at 97mm or 103mm. This makes all the readings unreliable. It would have been a wiser choice to use something with a point, so the width would be less than 1mm. This would make the results much more accurate and reliable.

The most important thing in the test was the wire. We carefully thought out what type of wire and what thickness it would be. But we only tested one strand of wire. As explained before the results were not exactly as expected. The wire could have had imperfections in the width of it. Or there could have been a kink or bend in the wire. If I was to conduct the experiment again I would do the experiment on about 3 or 4 different pieces of wire to ensure that results were accurate and unreliable.

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

# Related GCSE Electricity and Magnetism essays

1. ## Draw stress and strain graphs for the metal copper and the alloy constantan. Calculate ...

4 star(s)

Again this is due to it properties as an alloy, which makes it have a high young's modulus. The young's modulus is how stiff a material is. In metals the atoms are ionised and free electrons in between the ions.

2. ## Resistance of a Wire Investigation

The pointers would be more accurate because the tips have a much smaller area than the crocodile clips giving a more accurate measurement of the length of wire. As well as making these modifications I would also improve my Investigation by testing the same wire but different widths of that wire.

1. ## Physics GCSE Coursework:Factors affecting the resistance of a wire

Seeing that as I have chosen a range of 10 as to plot an accurate graph I will need at least 10 points to mark on the graph. I have also chosen to take 3 repeats at each length and then take an average.

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

in volts J = energy transferred in joules Q = charge in coulombs Potential difference is measured using a voltmeter. To measure the p.d across a component then the voltmeter must be connected in parallel to that component. Testing with a voltmeter does not interfere with the circuit at all.

1. ## Discover the factors affecting resistance in a conductor.

A steady increase in resistance, in a circuit with constant voltage, produces a progressively (not straight line if graphed) weaker current. The formula is written as I - V/R, or R = V/I. This formula can be used to make calculations with the values of V for a given conductor.

2. ## The resistance of wire.

The equation for resistance = V/I Results SWG (thickness/mm) Voltage/volts Current/amps V/I=R/ohms Average R/ohms Thickness investigation (Length kept constant at 15cms) Graph 1 - relationship between the wire's thickness and its resistance wwff ffw esffffs ayff ffba nff kcff ffuk.

1. ## Electromagnetism - investigating what effect increasing the number of turns in a coil on ...

Another way I could have improved my readings, the strength to a more accurate number, would to place an iron bar on a pair of scales then increase the strength of the electromagnet by adding more coils an investigate to see if the iron bar gets lighter.

2. ## Resistance Investigation. My aim in this investigation is to measure the amount of resistance ...

This could influence the investigation in a way such that the amount of resistance in each measurement would relatively increase because

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