• 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

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

Extracts from this document...

Introduction

Resistance of a Wire

Investigation

Aim

To investigate how the length of a wire affects its resistance.

Introduction

Electricity flows through some things better than others. How well something conducts electricity is measured by its resistance. Resistance in a wire depends on how thick the wire is, how long it is and what it's made of. The lower the resistance of a wire, the better it conducts.

There are many other factors that affect how much resistance an object has. The factor that I will be investigating will be the length of wire, and how this affects the amount of resistance the wire has.

Background Knowledge

The knowledge that I already have on this topic is on Ohms law and how to measure resistance using a voltmeter and an ammeter.

Ohm's law says that the amount of current flowing in a circuit is directly proportional to the electromotive force put on the circuit. This means that if you double the number of batteries in a circuit, the current flowing through the circuit will also double. Similarly, Ohm’s law states that the current flowing through a circuit is inversely proportional to the total resistance of the circuit. This means that if I double the current in a circuit, the resistance will drop by double the amount. Using Ohm’s law I can work out the resistance when I know the current and voltage.

Middle

1.52

2.04

1.64

2.04

1.62

20

2.60

1.04

2.84

1.12

2.79

1.13

30

2.98

0.81

3.21

0.84

3.19

0.86

40

3.70

0.64

3.46

0.69

3.52

0.68

50

3.71

0.57

3.64

0.58

3.06

0.59

60

3.72

0.50

3.75

0.50

3.77

0.50

70

3.86

0.43

3.87

0.45

3.88

0.49

80

3.94

0.39

3.99

0.40

3.96

0.40

90

4.04

0.36

4.08

0.36

4.00

0.36

100

4.10

0.33

4.09

0.33

4.11

0.33

My results show that the higher the voltage, the lower the current and I believe that this true for all of the results. Because I have compared my data with three experiments I believe that all of the data is accurate – though, the 50cm experiment on the third test is slightly out of place. This can be put down to a unique error in the reading of the result or a sudden fault in the voltmeter. However, the most probable cause of this irregular result is the change in the surrounding temperature. Temperature affects the resistance because if the wire is heated up, the atoms in the wire will start to vibrate more rapidly. This will cause more collisions between the electrons and the atoms due to atoms moving into the path of the flowing electrons.

Now, I will find the resistance for each test as I have the voltage and current. After working out the resistance I will find the average of the resistances. Taking the average is a more accurate method of measurement of a wide range of readings.

Conclusion

As well as making these modifications, I could also expand on my investigation by testing the same wire but different widths of that wire. I think the circuit and method used was suitable as it was very time efficient to work with. However, if I had time, I would do the experiment again but changing the separate lengths of wire each time.

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. ## Investigating how the length of wire affects its resistance

3 star(s)

seems to be a point that is further way from the line than others. When the length of wire is 50 cm (the longest length I used), the resistance was 7.08. Looking at my trend line, the point at 50cm should have been a bit less than 6.5 ohms instead.

2. ## Investigating how the length of a Wire affects its resistance.

When a thermisters is heated, the resistance is decreased because electrons in the semiconductor (silicon) are freed from its nucleus. This decreases resistance. If extreme accuracy is needed, a thermister can be used in conjunction with a suitable wire so that their effects cancel out i.e, because the resistance of

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

Therefore, the gradient of the graph will slowly decrease as the cross-sectional area increases. Fig. 1.9.2.1. Predicted graph of resistance against c.s.a. 1.10. Variables table: This experiment involves several variables, some of which are not noticeable at a glance. However, all of these variables are involved in determining the resistance of the wire.

2. ## How length affects resistance in a wire

diagram showing what my actual circuit diagram will look like which I am testing in preliminary: This is a diagram of the circuit that I will use in my experiment. During preliminary I will test if it all works well and if it does I will use this circuit for my real experiment.

1. ## &amp;quot;Are rechargeable batteries more economical than alkaline batteries?&amp;quot;

a contact check showed that by providing greater pressure to the poles, it was still able to give a little spot of light. However, soon after the light was gone. Only Rayovac Maximum was able to reach just before the 12-hour observation.

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

So a thin wire has more resistance than a thick one. * Material - A nichrome wire has more resistance than a copper wire of the same size. * Temperature - For metal conductors, resistance increases with temperature. For semiconductors, it decreases with temperature.

1. ## To Investigate How Length Affects the Resistance of a Length of Wire.

The free electrons are given energy and as a result move and collide with neighbouring free electrons. This happens across the length of the wire and thus electricity is conducted. Resistance is the result of energy loss as heat. It involves collisions between the free electrons and the fixed particles of the metal, other free electrons, and impurities.

2. ## Investigating how the length of a wire affects its resistance.

rheostat is set at a constant resistance to control the current: 0.5 amps, (To measure the current, voltage and the lengths of the wire accurately to two decimal places. (The apparatus that I will use is: (A power pack, (Wires, (A metre ruler stick, (Wire cutters, (Plastic tape/ Masking tape,

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