• 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

# To investigate how the resistances of a metal alloy (constantan) is affected by the length of the wire and by different amounts of voltages.

Extracts from this document...

Introduction

## A/S Physics Coursework - Resistance of a Wire

AIM

To investigate how the resistances of a metal alloy (constantan) is affected by the length of the wire and by different amounts of voltages.

## Theory

What is resistance?

Electricity is conducted through a conductor, in this case wire, by means of free electrons. The number of free electrons depends on the material and more free electrons means a better conductor, i.e. it has less resistance. For example, gold has more free electrons than iron and, as a result, it is a better conductor. The free electrons are given energy and as a result move and collide with other free electrons. This happens across the length of the wire, and allows electricity to be conducted. Resistance occurs when collisions between the free electrons and the fixed particles of the metal and other free electrons occur. This converts some of the energy carried by the electrons into heat energy, and this is resistance.

How is resistance calculated?

The resistance of a length of wire is calculated by measuring the current present in the circuit and the voltage across the wire. These measurements are then applied to this formula:

V = I * R

This can be rearranged to:

R = V/I

Middle

0.6

0.12

5

100

0.7

0.14

5

100

0.8

0.14

6

100

0.9

0.16

6

100

1.0

0.18

6

average resistance

5.1

Length (l)

Voltage (V)

current (A)

resistance Ω

90

0.1

0.02

5

90

0.2

0.04

5

90

0.3

0.07

4

90

0.4

0.10

4

90

0.5

0.12

4

90

0.6

0.14

4

90

0.7

0.16

4

90

0.8

0.18

4

90

0.9

0.2

5

90

1.0

0.24

4

average resistance

4.3

Length (l)

Conclusion

Also as I continued to take down results I realized that even though I was leaving the wire with 30 seconds to cool down in-between different lengths it still remained hot as I continued to write down results. If I were to repeat the experiment I would allocate a greater amount of time to take results and in turn more time to allow the wire to cool between results instead of having to continue the experiment with the warm wire.

Another problem was that arose was the equipment I had to use, it was unreliable and took me some time to find enough working components to complete the circuit. If I were to repeat the experiment I would use more up to date equipment which would lead me to more accurate results.

And finally the last thing I would add to my experiment to improve it would be to collect more results. This would enable me to draw a more accurate graph of my results and then in turn allow me to reach a better conclusion.

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. ## Investigate young's modulus behind Constantan and Copper.

4 star(s)

It is therefore mixed with other metals and melted. When carrying out this experiment I deem that as the number of weights is increased for copper, this will slowly exert pressure and the molecules will slowly pull apart as the bond will break between the molecules.

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

4 star(s)

of both materials and if this affects the ductility, tensile strengths and other physical aspects of the materials. Prediction using scientific knowledge: I would predict that the young's modulus of constantan will be higher than copper as it is an alloy and as we know alloys are generally less ductile and harder than pure metals.

1. ## Resistivity.My aim is to measure the resistivity of the wire alloy Constantan

I repeated the experiment once again just to make sure there were no outlying results. Safety Considerations, I will make sure I am wearing safety goggles at all time to prevent the wire damaging my eyes. I will keep the voltage passed through my wire below 3 Volts so the wire does not heat up.

2. ## Resistance of a wire - a number of experiments were carried out to determine ...

Any Factor that causes there to be additional obstacles or makes it more complicated for the electrons to flow will develop the resistance of the conductor by decreasing the rate of flow of charge. Resistance The resistance of a conductor is its opponent to the flow of electrons through it.

1. ## Investigating the resistivity of constantan

Using the gradient of a best fit line, I will work out the resistance of that particular length. I will then plot resistance against length to see its relationship. I will then work out resistivity using the equation: p=RA l Results 10cm 20cm Voltage (V)

2. ## To investigate how the Resistance of a Constantan Wire is affected by its length

Preliminary results: - The reason for doing preliminary research was to get an indication of the patterns I could expect in my results. Also, it was considered a practice, so if any errors were made in the first attempt, then they could be eradicated in my real experiment.

1. ## Investigation is to find out how the resistance of a wire is affected when ...

colliding with the atoms and this decreases a tiny bit of the current, and increases the resistance. The metal atoms become ionised when hit by electrons. The longer the wire gets, it will have more resistance as there is a larger chance for the moving electrons to collide in the atoms.

2. ## To investigate the factors which effect the resistance of a metal wire.

If the resistance is high, the flow of electrons is slowed down and so the number of electrons per second is reduced meaning that the current is reduced. Now, the factors that affect the resistance of a wire are going to be described.

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