• 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

# Investigating the factors affecting the resistance in a piece of wire.

Extracts from this document...

Introduction

Helen Bewick 10C

Investigating the factors affecting the resistance in a piece of wire

Planning

Resistance- Resistance is a force which opposes the flow of an electric current around a circuit so that energy is required to push the charged particles around the circuit. Resistance is measured in ohms.

During this experiment I aim to research and plan an experiment to investigate a factor that affects the resistance in a piece of wire.

The possible factors I could change in this investigation are:

1. Length of the wire,
1. Thickness of the wire,
1. Type of metal- Copper, Nichrome and constantan
1. Shape of the wire,
1. Temperature of the wire,
1. Density of the metal.

I have chosen to investigate the length of the wire because length is a continuous variable with a continuous range so I will be able to choose any lengths to investigate.

I chose not to investigate thickness because although it is a continuous variable the wires available to me only come in set thickness that do not go up in regular intervals.

I chose not to investigate type of metal because it is not a continuous variable so I would not be able to evaluate the investigation by linking two or more groups of data on a graph.

I chose not to investigate the shape of the metal because it isn’t a continuous range. I could only use two options bent or straight.

I chose not to investigate the temperature because although it is a continuous range it is very difficult to maintain a temperature, as you couldn’t use a water bath because of safety aspects. It is also difficult to measure the temperature of a piece of wire.

Middle

The resistivity of Nichrome at 250C is 100 x 10-8 ohm-m. The radius of the wire is 0.00014m2. To find the area of a cross section of the wire i use the equation for the area of circle

Area of circle = πr2

Area of circle  = π x 0.000142

Area of circle = 6.16m2 x10 -8

Working to find the resistance

To predict resistance for a length of wire of 10cm I use the equation,

Resistance  = resistivity x length / area of cross section of the wire

Resistance = 100 x 10-8 x 0.1m / 6.16m2 x 10 –8

Resistance = 1.62 Ω rounded 2 d.p.

To predict resistance for a length of wire of 20cm I use the equation,

Resistance  = resistivity x length / area of cross section of the wire

Resistance = 100 x 10-8 x 0.2m / 6.16m2 x 10 –8

Resistance = 3.25 Ω rounded 2 d.p

To predict resistance for a length of wire of 30cm I use the equation,

Resistance  = resistivity x length / area of cross section of the wire

Resistance = 100 x 10-8 x 0.3m / 6.16m2 x 10 –8

Resistance = 4.87 Ω rounded 2 d.p

To predict resistance for a length of wire of 40cm I use the equation,

Resistance  = resistivity x length / area of cross section of the wire

Resistance = 100 x 10-8 x 0.4m / 6.16m2 x 10 –8

Resistance = 6.49 Ω rounded 2 d.p

To predict resistance for a length of wire of 50cm I use the equation,

Resistance  = resistivity x length / area of cross section of the wire

Resistance = 100 x 10-8 x 0.5m / 6.16m2 x 10 –8

Resistance = 8.12 Ω rounded 2 d.p

To predict resistance for a length of wire of 60cm I use the equation,

Resistance  = resistivity x length / area of cross section of the wire

Resistance = 100 x 10-8 x 0.6m / 6.16m2 x 10 –8

Resistance = 9.74 Ω rounded 2 d.p

To predict resistance for a length of wire of 70cm I use the equation,

Resistance  = resistivity x length / area of cross section of the wire

Resistance = 100 x 10-8 x 0.7m / 6.16m2 x 10 –8

Resistance = 11.36 Ω rounded 2 d.p

Conclusion

• I left the power pack on too long. This causes the wire to overheat.
• When I was measuring the lengths of the Nichrome wire my measurements might have been slightly inaccurate. The rulers used might not have been exact and it was difficult to get an accurate reading of length by eye as the wire was not completely straight. Also the ruler may have been of different thicknesses throughout the length. This would have contributed as a slight error in my results.
• The ammeter and voltmeter could have been slightly faulty and not given me correct, accurate readings.
• I connected the wire into the circuit using crocodile clips. These were quite loose and so this could have made my results less accurate. If I improved my method I could either attach the wires with tape but this may affect my results so instead I could solder the Nichrome wire into my circuit.
• It was difficult to adjust the variable resistor slider accurately only by eye. If I did the investigation again I could try to and adjust the variable resistor accurately I will use an advanced digital variable resistor.
• I also found it difficult to measure exact lengths against the meter rule because the crocodile clips didn’t clip on to the wire very securely. If I did the investigation again I could pre cut all the lengths of wire before the experiment instead of just connecting the crocodile clips at different distances apart on the meter rule.

To further my investigation I could use the same method but increase the range of lengths. I could use lengths of up to 3 meters. I could take readings from lengths at smaller intervals; I could take reading every 5cm instead of every 10cm as I did. I could also take more repeat readings to get a even more accurate average.

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

3 star(s)

The electrons skip from atom to atom in the metal in retort to the electric field in the circuit. A conductor with a larger cross-section allows more electrons to relate with the field. Because there is more current with a given voltage, a conductor with a larger cross-section has lower resistance.

2. ## An Experiment To Find the Resistivity of a Wire

The results support my predictions well. Doubling the length did double the Resistance as seen in the table above. This wasn't true for all cases as when the wire of length 0.50m with a resistance of 0.74ohms was doubled, the Resistance had an error of 12.8% and did not agree with the other results.

1. ## An experiment to find the resistivity of nichrome

ensure a greater accuracy in the obtained results and in the plotted graph. Length of the wire: - At the beginning when I did a preliminary experiment I was using crocodile clips instead of terminal blocks to connect the wire to the circuit.

2. ## Factors Affecting the Efficiency of a Wind Turbine

My hypothesis wasn't correct in that the larger the angle the greater the efficiency of a windturbine. This is what I was expecting but it wasn't true in this instance. What makes a small angle achieve a better performance? When you have three different angles as shown in the diagram below.

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

Length is a non-linear variable because I don't expect it to be directly proportional to current. I previously considered investigating the cross-sectional area of the wire because this factor is probably the most effective one that has the greatest influence on the current in a wire.

2. ## The resistance of wire.

the method; if I had any problems I could correct them there and then. This would mean I would obtain precise and reliable results in my main experiment when investigating the connection between the length of the wire and the resistance of the wire.

1. ## How the length of nichrome wire affects the resistance

35 0.38 2 5.3 40 0.33 2 6.1 The preliminary test shows: As the length or the wire increases, the current decreases. As the length of wire increases, the voltage increases but after 25cm, the voltage stays at 2v. As the length of wire increases, the resistance increases.

2. ## Investigate the resistance of different wires and how at different lengths the voltage increases ...

Secondary source data For my secondary source data I shall be using other pupil's results from my class and I will compare those to mine. I am going to be comparing there data with mine on graphs to see who's are the most accurate, match my prediction the most, and if most importantly they are along the amounts.

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