• 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
9. 9
9
10. 10
10
11. 11
11
12. 12
12

# Resistivity of a Wire

Extracts from this document...

Introduction

Resistivity of a Wire

Aim:

The aim of this investigation is to see how the length of Nichrome wire affects its resistance

Pre-test Results:

 Wire Type Swags Length of Wire(cm) Voltage(v) Current(a) Resistance(Ω) Constantan 26 102040 13.527.556.4 0.4 37.5687.51410 Copper 26 102040 0.91.52.5 0.4 22.537.562.5 Nichrome 26 102040 32.559.4118.3 0.4 812.514852957.5

Pre-test Findings:

From my pre-test, I found out that using the nichrome wire would be best to use because it gave the both more reliable results and were also closer together. Constantan was not suitable for the investigation because it gave very inaccurate results- the range was very large. Copper was not suitable both because it had a very low resistance, and also heated up very fast, so could burn someone. Therefore I decided to use nichrome wire.

I also decided to use a wooden block to keep hold of the wire, because it will keep the wire taut and also to prevent anyone getting burnt.

Another thing I decided was to use digital multimeters because they give more accurate results- to 2dp- and can measure both the current and voltage on the same instrument.

The ranges of lengths I will be using for my final investigation are: 0.2m, 0.4m, 0.6m, 0.8m and 1.0m.

Fair Testing:

Middle

0.000000159

0.2m = 0.2 x (110 x 10-8) ÷ 0.000000159 = 1.38 Ω

0.4m = 0.4 x (110 x 10-8) ÷ 0.000000159 = 2.77 Ω

0.6m = 0.6 x (110 x 10-8) ÷ 0.000000159 = 4.15 Ω

0.8m = 0.8 x (110 x 10-8) ÷ 0.000000159 = 5.53 Ω

1.0m = 1.0 x (110 x 10-8) ÷ 0.000000159 = 6.92 Ω

Prediction Continued:

I also predict that the resistance is directly proportionate to the length of the wire. If you double the length of nichrome wire, so will the resistance. From my predicted results, I can see that when I double the length from 0.2m to 0.4m, the resistance almost doubles too, from 1.38Ω to 2.77Ω. In the same way, if I triple the length of wore from 0.2m to 0.6m, the resistance is once again almost triple, from 1.38Ω to 4.15Ω. This also works if I quadruple the length of the wire from 0.2m to 0.8m and if I increase the length of wore 5 times, the resistance also increases in the same way. This can be seen not only when using 0.2m of wore but also if I double the length of wore from 0.4m to 0.8m, the resistance is almost double too, from 2.77Ω to 5.53Ω. This is because there is 2, 3, 4, or 5 times the length of wore, which means that there will also be 2, 3, 4, or 5 times more nichrome atoms present in

Conclusion

In order for the investigation to be fairer, I think the temperature of the wire should have been kept constant. This had an effect on the investigation, because from my research, I found out that another factor affecting the resistance in a wire was the temperature too. As the temperature of the wire increased, so did the resistance. This is because as the wire gets heated, the particles gain kinetic energy, therefore making the flow electrons harder. This makes the particles move around more, therefore colliding with the electrons, and blocking their way, and taking longer for the electrons to move to the other side of the wire. This results in an increase of resistance.

It would be very difficult for the temperature of the wire to be kept constant. A water-bath would not be suitable because there would be a potential health hazard, as water is an excellent conductor of electricity.

There is however a device known as a thermocouple, which can help us check the temperature is at a constant level or not. How it works is that it is connected in the circuit. They work in the sense that if the temperature of the wire goes above a given temperature, the thermocouple stop working, therefore breaking the circuit and so will not work.

Zoya Khan         1354        13228

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

I think this error may have been as a result of the connections made between the doubled or tripled diameter of the wire and the crocodile tips, while conducting the experiment for the different cross sectional area as it was difficult to try and fit the wires firmly to the tip of the crocodile clips without actually twisting them together.

2. ## Resistance of a Wire Investigation

If we look at light as a wave phenomenon, we can assign it a wavelength (the distance from one peak of the wave to the next) and an amplitude (the distance the wave oscillates from its centreline). Different wavelengths of light have different characteristic energies and properties.

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

Justification of the equipment range: - Ammeter: - I used a full scale deflection ammeter of current range from 0-1A because I only wanted to measure small currents passing through the circuit and not large currents however all the digital ammeters that were available had a current range of 0-20A

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

All blades will have the same angle each time. Every other variable will be kept constant. Apparatus Apparatus used in this experiment are: - 1. Dynamo 2. Hairdryer 3. Blades (made of Copper) 4. Wooden Cork 5. Retort stand 6.

1. ## Investigating the resistivity of an unkown wire

When a metallic wire is placed in an electric circuit, the voltage from the battery makes the electrons flow through the wire. As they do so, they collide with the metal ions in the wire and this process slows down the gradual continuous flow of the electrons.

2. ## Investigation of Resistivity of Nichrome wire

The dimensions were 32 gauge and length of 1 metre. It was attached to the apparatus. The power supply was set to 2 volts and the current and voltage was measured using the voltmeter and ammeter respectively. Readings were recorded in the results table.

1. ## Calibration of a Thermocouple.

A problem with working with thermocouples is that it needs a sensitive voltmeter, able to detect a signal of the order of a thousandth of a volt. Too sensitive a detector, and there appears to be no temperature difference. Another problem is the problem of internal resistance of a source.

2. ## Determination of the resistivity of nichrome wire

This causes more collisions between the electrons and the atoms as the atoms are moving into the path of the electrons. This increase in collisions means that there will be an increase in resistance. An increase in resistance will lead to an increase in resistivity.

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