• 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

# An experiment to investigate how the length of a wire affects its resistance.

Extracts from this document...

Introduction

## An Experiment to investigate how the Length of a Wire affects its Resistance

Aim: This experiment will show us varying the length of a piece of wire will affect the resistance of the wire.

Introduction: Using Ohms law (V = I x R), we will calculate the resistance in a wire. Our only variable will be the length of the wire, because the thickness, temperature or type of wire will give us inaccurate results. So, to keep this fair, we will only alter the length. We will measure the resistance by taking readings from a Voltmeter and an Ammeter and using them to calculate the resistance.

Background Knowledge: Resistance in a wire will depend on many different factors. One of which that is important is the thickness of the wire.

Preliminary Experiment:

A computer with ‘Scientific Investigator’ installed.

Preliminary Method

Middle

1.38

0.25

90

1.4

0.23

1.39

0.23

1.39

0.23

1.393

0.23

100

1.4

0.21

1.4

0.2

1.4

0.21

1.4

0.206

Preliminary Calculations: To calculate resistance, we take V (Voltage) and divide by I (Current) to give the resistance in Ohms Ω.

 Length of wire (cm) Resistance (Ohms Ω) 10 0.933 20 1.515 30 2.079 40 2.835 50 3.49 60 4.058 70 4.857 80 5.52 90 6.057 100 6.796

Prediction: This prediction is much the same as the preliminary one. As the length of the wire increases, the resistance will also increase. Also,  for 0cm the resistance should be 0, but I think that it will not work like this as there will always be voltage and current being measured, however I expect it to be less than the 10cm reading.

Equipment:

Ammeter – 0-5 Amperes

Voltmeter – 0-5 Volts

Wires – Insulated

Bare wire – 0.37mm thick, length of 100cm

Power supply – 6 volts

Two Crocodile Clips (labelled X and Y on diagram)

1m Ruler

Method/Fair Test: To keep this test fair, we will keep the temperature constant and use the same equipment throughout.

Conclusion

1.126

30

2.88

0.9

2.96

0.95

2.82

0.95

2.707

0.923

40

3.25

0.78

3.25

0.73

3.17

0.73

3.223

0.753

50

3.47

0.67

3.37

0.66

2.47

0.66

3.336

0.646

60

3.66

0.59

3.56

0.58

3.52

0.58

3.58

0.576

70

3.8

0.5

3.68

0.52

3.64

0.52

3.706

0.51

80

3.94

0.46

3.79

0.46

3.76

0.46

3.88

0.466

90

4.01

0.43

3.86

0.42

3.84

0.42

3.903

0.436

100

4.06

0.4

3.89

0.38

3.89

0.38

3.946

0.386

Calculations: To calculate resistance, we take V (voltage) and divide by I (current)

 Length of wire (cm) Resistance (Ohms Ω) 0 0.397 10 1.2067 20 2.1607 30 2.9328 40 4.2802 50 5.1641 60 6.2153 70 7.2667 80 8.3262 90 8.9518 100 10.2228

Conclusion: In conclusion we have found positive correlation between resistance and wire length, as stated in the theory and my prediction. Another point is that the line of best fit does not pass through the origin, which proves that there is resistance even when there is no wire. I believe that this was caused by the rest of the wire going to the voltmeter, or perhaps some other error.

Roughly, the length of the wire divided by ten gives us the resistance. Although this would not work with other variables altering resistance, we would still see similar correlation.

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 how the length (mm) and the cross-sectional (mm2) area of a wire ...

as the length of the wire increased, the resistance would increase as well, and as the cross-sectional area increased, the resistance would decrease. This was due to electrons colliding with atoms in the wire and losing energy, causing resistance. Since I have drawn the graphs, I will now analyse them

2. ## Investigation: How length affects the resistance in a wire.

"|¾ " ________________ " " ""8âÿ?ÿâ """"""ÿÿÿÿ "ƒigÿ!i""#"ƒigÿ\$i%"&"'(")"*+",ÿÚ"")""ï¿½"æ ",c"Ô”"|¾"8c "|¾ " ________________ " " ""8âÿ?ÿâ """"""ÿÿÿÿ "ƒigÿ!i""#"ƒigÿ\$i%"&"'(")"*+",ÿÚ""Å½""ø"FD ________________ ",c"Ô”"|¾"8c "|¾ " ________________ " " ""8âÿ?ÿâ """"""ÿÿÿÿ "ƒigÿ!i""#"ƒigÿ\$i%"&"'(")"*+",ÿÚ""ù""h"¢ ",c"Ô”"|¾"8c "|¾ " ________________ " " ""8âÿ?ÿâ """"""ÿÿÿÿ "ƒigÿ!i""#"ƒigÿ\$i%"&"ƒigÿ'i(")"*+",ÿ ________________ "Ú""‡""ò"°Å½ ________________ ",c"Ô”"|¾"8c "|¾ " ________________ " " ""8âÿ?ÿâ """"""ÿÿÿÿ "ƒigÿ!i""#"ƒigÿ\$i%"&"'(")"*+",ÿÚ""ó""\"FD ________________ ",c"Ô”"|¾"8c

1. ## An Experiment To Investigate How The Length Of A Wire Affects The Resistance

The most common type is the carbon resistor, made from compressed carbon of known resistivity. The amount of resistance of a conductor depends on several factors: * Length - Doubling the length of a wire doubles its resistance. * Cross-sectional area - Halving the 'end on' area of a wire doubles its resistance.

2. ## Did a Secret Military Experiment Cause the 2003 American Blackout?

Despite the claims of HAARP advocates, ionospheric heaters can use the ionosphere to reflect their energy at distances several thousand miles away by using the ionosphere as a 'mirror' much the same way as AM radio signals travel over vast distances.

1. ## An Experiment To Investigate How The Length Of A Wire Affects The Resistance

The most common type is the carbon resistor, made from compressed carbon of known resistivity. The amount of resistance of a conductor depends on several factors: * Length - Doubling the length of a wire doubles its resistance. * Cross-sectional area - Halving the 'end on' area of a wire doubles its resistance.

2. ## To investigate how length affects the resistance of a length of wire

Throughout the experiment Constantan will be used. The type of material will affect the amount of free electrons that are able to flow through the wire. The number of free electrons depends on the amount of electrons in the outer shell of the atoms, so if there are more or larger atoms then there must be more electrons available.

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