• 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
13. 13
13
14. 14
14
15. 15
15
16. 16
16
17. 17
17
18. 18
18
19. 19
19
20. 20
20
21. 21
21
22. 22
22
23. 23
23
24. 24
24
25. 25
25
26. 26
26

# In this investigation I'll attempt to find out how electrical resistance varies for two different conductors, nichrome and constantine, when changing the length and the thickness of the wire.

Extracts from this document...

Introduction

Mitchell Black                Physics Coursework

Physics Coursework

Investigation into the Factors affecting the Resistance of a Conductor

By Mitchell Black

April 2003

Introduction

In this investigation I’ll attempt to find out how electrical resistance varies for two different conductors, nichrome and constantine, when changing the length and the thickness of the wire.

## Variables

1. Length – The longer the length of the wire the further the electrons will have to travel along it, increasing the resistance. Because of this the length increase should be proportional to resistance increase.
2. Cross section of the wire - If the wires width is increased the resistance will decrease. This is because of the increase in the space for the electrons to travel through. Due to this increased space between the atoms there should be less collisions.
3. Voltage passed through the wire – The higher the voltage the more electrons there will be passing through the wire, this should cause more collisions, causing higher resistance.
4. Temperature – Resistance produces heat, but heat also increases resistance. This is because the atoms in the wire vibrate more due to their increased energy. This causes more collisions with the electrons as the atoms vibrate into the path of the electrons.
5. Type of wire used – Obviously different conductors have different resistivity, so the same conductor should be used throughout the experiment.

For this experiment I will keep voltage, temperature, and the type of wire used constant.  I shall vary length and cross section of the wire, as these are the factors I’m investigating.

Middle

1. Steps 1-5 will then be repeated with Nichrome wire of width SWG26 SWG28 SWG36 and SWG40.
1. The same will be done for Nichrome wire.

As the SWG number increases the cross sectional area of the wire decreases.

Results

## Results for different thicknesses of Constantine wire

 Length Resistance SWG 22 Resistance SWG 26 Resistance SWG 28 Resistance SWG 36 Resistance SWG 40 5cm 0.9 1 0.8 1.7 2.8 10cm 1 1.1 1 2.5 4.9 15cm 1.1 1.3 1.3 3.2 7.2 20cm 1.1 1.3 1.5 4 8.9 25cm 1.4 1.7 1.6 4.7 11.1 30cm 1.6 2.1 1.9 5.5 12.9 35cm 1.3 2.5 2.1 6.4 16.6 40cm 1.6 3.0 2.6 7.3 17.3

## Results for different thicknesses of Nichrome wire

 Length Resistance SWG 22 Resistance SWG 26 Resistance SWG 28 Resistance SWG 36 Resistance SWG 40 5cm 1.0 2.1 2.2 3.7 7.3 10cm 1.1 2.4 2.8 5.7 11.1 15cm 1.3 2.7 3.3 7.6 16.3 20cm 1.5 3.1 3.8 9.4 20.7 25cm 1.7 3.4 4.3 11.4 26.0 30cm 1.8 2.8 3.6 12.1 29.3 35cm 2.2 4.0 5.2 15.2 35.2 40cm 2.4 4.4 5.9 17.4 40.6

## Area of Nichrome wire

SWG

Resistance (ohms)

### Area (cm)

Area x 10

1/area

22

0.0355

1.2

0.00396

39.6

252.52

26

0.0225

2.8

0.00159

15.9

628.93

28

0.02

3.6

0.00126

12.6

793.65

36

0.01

12.1

0.000314

3.14

3184.71

40

0.006

29.3

0.000113

1.13

8849.56

Conclusion

3 bar enough to effect results than a 2cm3 wire.Looking back on the procedure of my experiment I now realise that I should’ve taken 3 readings, and then found the average in order to gain more accurate results.I think that some of my anomalous results may be accounted for due to bad contact through the crocodile clip.  The only way I can see to get round this problem is to have boards especially made for this experiment, which have a sliding contact, which you slide to the correct length, and then somehow secure it to the wire.

Anomalies

The only anomalies I could identify were on the curved graph for constantine (area: resistance), it was using the SWG 28 board.  In turn affecting the graph for 1/Area of constantine, with an anomaly also on SWG 28To me this suggests that the board was faulty, maybe there was a kink or a bend in the wire.  I’ve circled this results on the graph.  Also I’ve marked in where I’d expect it to be in pen.

Further Work

To take the investigation one step further, other factors could be investigated, such as voltage.  Using the same two metal wires, on a relatively medium thickness (such as SWG 28), connected to an ohmmeter.  The voltage should be increased, and the resistance reading recorded each time.  I think this investigation would show that as the voltage increases so does the resistance, because more voltage means more electrons moving around and colliding, and colliding electrons cause resistance.  The graph would look something like the sketch below.

Resistance

(Ω)

Voltage (Volts)

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. ## The factors affecting the resistance of a metalic conductor.

4 star(s)

However I must verify these facts form my graph and calculate the value of R from the graph. Here are my results: For the thickness of the wire: > 0.4mm Gradient = 0.25 - 0.15 / 1.25 - 0.82 = 0.1/ 0.43 = 0.21 Therefore; R = 1/0.21 = 4.8

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

This is because of the scientific idea stated earlier that if you double the length, you double the number of atoms therefore increasing the number of collisions, the current carrying charged particles make with fixed particles thus doubling the resistance.

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

heat up the wires thus damaging the circuit and affecting the resistivity of nichrome. Voltmeter: - I chose to use a digital voltmeter of range 0-5V instead of a full-scale deflection voltmeter to avoid parallax error when recording the voltage readings.

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

for a wire of larger cross sectional area, and would be expected to depend upon the material out of which the wire is made. Experimentally, the dependence upon these properties is a straightforward one for a wide range of conditions, and the resistance of a wire can be expressed as

1. ## Resistance of a Wire Investigation

The ammeters and voltmeters could have been damaged and reading falsely on both the meters used. Measuring the lengths of the wire is also a inaccuracy as the rulers used are not exact, and it is difficult to get an accurate reading of length by eye, as the wire might

2. ## An in Investigation into the Resistance of a Wire.

This can be done with a variable resistor or rheostat. Adjusting the rheostat changes the length of the wire that the current has to flow through. The type of material will also make a difference in the resistance because the electrons have to pass through the material and there are also different amount of electrons around the particles.

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

As mentioned, when the voltmeter/ammeter method is being used, a power-pack will be needed, keeping the power levels constant. My results showed that when the length increased, the resistance increased to show that they are directly proportional. I hope to see a very similar trend of results when I perform

2. ## Investigation of Resistivity of Nichrome wire

Readings were recorded in the results table. This was repeated at different volt settings, 4 - 16 volts. The whole procedure was once again repeated for another nichrome wire of different dimensions, being at 28 gauge and of 0.5 metre. Results Table 1: the resistivity of nichrome wire at 32 gauge and 1 metre length.

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