• 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

# Resistance of a Wire

Extracts from this document...

Introduction

Background scientific knowledge

## Electricity

Electricity is the movement of charge (electrons) around a circuit. The charge flows throw conductors which allow the electrons to pass through. An object which does not allow electrons to pass through is an insulator.

Conductors intended to have resistance are called resistors (symbol            )

Voltage- given the symbol V, measured in volts using a voltmeter

Current- given the symbol I, measured in Amperes using an ammeter

## Resistance

Resistance is the ability to prevent or resist the flow of electrical current. Resistance occurs in an electrical circuit because of a collision between electrons and atoms, which slows the electrons down and converts some of their KE to heat energy. Resistance is measured in Ohms (Ω).

## Diagram

Arrow shows direction of electron movement through the wire.

## Equation

Factors which affect resistance

Length of wire – this is being investigated
Thickness of a wire

Middle

(I)

(Ω)

Expt. No

Length of

wire

Voltage

Ave

Current

Ave

Resistance

R=V/I

1

2

3

1

2

3

1

100cm

2

80cm

3

60cm

4

40cm

5

20cm

Graph showing length of wire against resistance

Resultstable

 (I) (V) (Ω) Expt. No

Conclusion

The results support my prediction as there was a bigger resistance in the longer pieces of wire compared to the shorter ones which had a smaller resistance.

Evaluation

The evidence is reliable as I minimised the chance of the wire heating up too much as I used a switch to turn it off when I wasn’t using it. I also took repeats and an average to make sure each result was fairly the same and there weren’t any anomalies.

There were some problems in the procedure as the wire still heated up and the measurement of the wire wasn’t very accurate as there was bends and kinks in the wire.

The improvements I could make are to make sure my measuring of the wire was accurate, to use a longer length of wire and to take more averages.

I couldn’t see any anomalies in my results or on my graph.

The other variables I could investigate arethickness of a wire and material of wire.

| Page

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

## Here's what a star student thought of this essay

4 star(s)

### Response to the question

A well set out experiment for this level. The candidate outlines the scientific knowledge of resistance well and relate it to the experiment to get an accurate prediction of what will happen during their experiment and what will be ...

### Response to the question

A well set out experiment for this level. The candidate outlines the scientific knowledge of resistance well and relate it to the experiment to get an accurate prediction of what will happen during their experiment and what will be shown in their results. It is good to back any statement up with valid scientific knowledge as this shows a deeper understanding of the subject and consideration of the experiment and what the results will mean. The candidate makes an accurate evaluation of the experiment but they could include further improvements upon the problems they encountered but this is only an addition as they already provide a good range of possibilities. The conclusion is accurate based on the rest of the experiment.

### Level of analysis

The candidate includes a background scientific knowledge section which is really good because it helps the reader understand that the candidate possesses all basic knowledge to make an accurate prediction about the experiment they are carrying out with solid scientific knowledge. Factors which affect resistance and why they do so are outlined well. Factors other than the one being investigated should be kept continuous so they do not bias the experiment. The candidate understands this, hence this is controlled by the candidate which shows a high level of understanding of resistance in this instance. The candidate outlines the method and how he will keep these constant, but one or two of the instructions are hard to interpret so the candidate should make this clearer to ensure the reader knows exactly what they are doing. The prediction of the candidate is good and draws on valid scientific knowledge to make a valid hypothesis.

### Quality of writing

In the method punctuation is inconsistent and this should be addressed so the writing does not look 'sloppy.' Otherwise, spelling, grammar and punctuation are to a good standard. The layout of the essay is good with clear subheadings for each different section.

Reviewed by skatealexia 10/07/2012

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. ## Investigation into the Physics of a Light Dependent Resistor.

4 star(s)

Therefore each electron receives the correct amount of energy but the higher amount of electrons means more electrons are freed, which as I have explained increases the overall voltage within the circuit. These facts (which incidentally I obtained from The Art of Electronics by Horowitz Hill 1980), went a long way to reassure me that my results were accurate.

2. ## resistance of a wire

3 star(s)

The constantan wire that I am going to use in the experiment is 60 cm long. So all in all I will have 6 results. On its own theses results are not that accurate, so we do the experiment another 2 times.

1. ## To investigate which fuel gives out the most energy when burnt. We are burning ...

It may have been due to the lid of the spirit burner not put on correctly leading to the evaporation of the alcohol or it may have just been an error in our calculations. My predicted graph and the graph showing my results are also very similar.

2. ## Electromagnets - What factors affect strength of an electromagnet?

The data is also continuous therefore line graph is most appropriate. The graph one shows the average number of paper clips attracted, when varying the number of turns. The line of best fit on graph one shows a positive correlation, which shows that an increase in the number of turns will attract more paperclips.

1. ## To find out what happens to the efficiency of a motor as I change ...

the efficiency of a motor is determined by how much of the electrical energy put in is transferred into useful energy output. The useful energy output is gravitational potential energy (GPE). Gravitational potential energy is the ENERGY STORED in an object because of the HEIGHT that the WEIGHT (due to the force of gravity on the object)

2. ## Experiment to investigate the energy given of in food stuffs.

So these are thing that we did to ensure that our experiment was fair. * As we are using two clamps, one for the test tube and one for the needle, we made sure that the clamp with needle was 1.5 cm away from the bottom of the test tube at all times.

1. ## Find the efficiency of energy conservation of a staple fired by an elastic band.

I decided to use the piece of string instead of holding the elastic band with my fingers and then taking the weights of with my other hand. This is because holding the elastic band at a specific extension with my fingers could increase or decrease the extension and so would effect my results very much.

2. ## Length vs Resistance

On the other hand, a wire with a larger diameter would mean less resistance as there would be more space for electrons to pass through, resulting in the power source not having to work as much to push the electrons around the circuit.

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