• 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

# What factors affect the flow of current through a wire?

Extracts from this document...

Introduction

Sreekar Charlu 1VCB                                                                             14th March 02

Physics Coursework

What factors affect the flow of current through a wire?

## Theory

Current is due to the flow of electrons. The material of the wire consists of layers of atoms whose positive centres (ions) are surrounded by a sea of electrons. These electrons are very mobile (free to move). However, when the electrons start moving, carrying current, they will keep on bumping into the ions. These ions, vibrating in fixed positions, cause obstruction to the free flow of electrons. This obstruction is termed resistance. Resistance opposes current and therefore the higher the resistance, the smaller the current. Therefore the factors that affect the resistance are the same factors that control the flow of current through a wire.

In the above diagram the circle represent the ions and the red line represents the flow of electrons.

The factors affecting the flow of current, which you could investigate, are:

• Area of cross-section of wire

When the area of cross-section of the wire is increased the current through it will increase. This is because the electrons can flow more freely through a large cross-section space available, with the same length of wire, and so avoid colliding

• Length of wire

## When the length of wire is increased the current is expected to decrease.

Middle

0.21

0.16

4.76

0.762

100

0.18

0.16

5.56

0.890

1. Table of Results
 Length (cm) Current (A) Voltage (V) Resistance (ohms) 10 1.63 0.16 0.613 0.098 15 1.29 0.16 0.770 0.123 20 0.91 0.16 1.10 0.176 25 0.71 0.16 1.41 0.2256 30 0.67 0.16 1.49 0.2384 35 0.57 0.16 1.75 0.280 40 0.44 0.16 2.27 0.3632 45 0.42 0.16 2.38 0.3808 50 0.40 0.16 2.50 0.400 55 0.36 0.16 2.78 0.4448 60 0.33 0.16 3.03 0.4848 65 0.31 0.16 2.23 0.568 70 0.28 0.16 3.57 0.5712 75 0.27 0.16 3.70 0.592 80 0.25 0.16 4.00 0.640 85 0.23 0.16 4.35 0.696 90 0.23 0.16 4.35 0.696 95 0.23 0.16 4.76 0.7616 100 0.18 0.16 5.56 0.889
1. Table of Results
 Length (cm) Current (A)

Conclusion

, with the gradient from my graph, a value of was obtained for the specific resistance () of constantan which worked very well with the literature vale (ref. Electricity made simple). These facts clearly show that my investigation was very successful and accurate. However, I did find some anomalous results which I could make more reliable throughout extended investigations.

Nevertheless, there were several areas that could have been improved. Accurate measurement of lengths is one such area and choosing wires of 100% uniform thickness with minimum requirements for straightening would help to increase accuracy and avoid anomalous values in the results. While random errors can be minimised by doing each step extra carefully any systematic errors due to instruments such as the ammeter and voltmeter can be overcome only by calibrating the ones used against accurate instruments.

Repeating each experiment under identical conditions will ensure reproducibility. Both reproducibility and accuracy are required in order to obtain an extremely successful outcome of an investigation. Using different thickness of wire could extend this experiment and also by using different materials, in order to demonstrate the correctness of the relationship  for the resistance of the wire. I could also extend this experiment by using different sets of cross-sections of the wire so I could prove which had the highest resistance and which one had the lowest resistance.

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

Because the difference between each 1 is not the same (which I had worked out earlier). Length This best fit curve on this graph in exponential. This graph agrees with my prediction. Because if you double the length, the current halves.

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

5 wires for ammeter/voltmeter experiment: To connect up the circuit 2 wires for the multimeter experiment: To connect the carbon putty to the multimeter Two Crocodile Clips: The crocodile clips are attached on the end of two of the wires to make contact with the 2p coins in the ammeter/ voltmeter experiment.

1. ## 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.

2. ## I am trying to investigate the factors, which affect the current in a wire.

I will connect an ammeter in series and a voltmeter in parallel to the mounted wire board. I will connect both an ammeter wire and voltmeter wire together and then move it in different distances along the wire, this will enable me to work out the voltage, current and consequently

1. ## Investigate how resistance can affect the amount of current flow.

flowing across the material. A material of high resistivity will require a higher electrical field to cause a given current density. If the resistivity of a material is known, as well as its dimensions, it can be used to calculate the resistance of a particular piece of material.

2. ## Investigating the factors which affect the flow of electricity

can be calculated using the equation: R =V I If we look at Ohms law, discovered by German physicist "Georg Ohm" in 1827, it states:" The current flowing through a resistor is directly proportional to the voltage across it. That is, if the temperature remains constant (The resistance has an affect on the flow of electricity)

1. ## Investigating the factors affecting the current flowing through a wire.

Variables The factors that affect the amount of current flowing through a wire are * Length of wire * Cross sectional area * Temperature * Material * Voltage I have chosen to vary the length of the wire The length of wire has an affect because in a long piece

2. ## What Factors Affect The Amount Of CurrentThat Can Flow Down A Wire

The things I could measure are: Current using an ammeter. This would tell me the amount of current flowing through the circuit. Resistance using a multimeter this would tell me in ohms the amount of resistance the wire had. My question will be how will the length of a piece wire affect the amount current flowing through it.

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