• 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 how thickness and length affect the resistance of particular wires.

Extracts from this document...

Introduction

Investigating how thickness and length affect the resistance of particular wires

Equipment

The equipment that I will need to perform this experiment will be:-

• Battery pack
• 5 Wires
• A volt meter
• An ammeter ( 0-15)
• Crocodile clips
• Ruler
• Nickel chrome wire

Method

The first thing that needs priority when setting up a circuit is safety. I will handle everything with dry hands and take extra care so that I don’t short circuit the experiment. The experiments will be investigating the relationship between the thickness of the wire and the length of the wire. I will connect up a circuit like shown above, the power supply coming from a power pack. A volt meter and an ammeter will be placed in series and the wire which I will be investigating, so will be changing, will run in parallel to the ammeter. The set up of the circuit will tell me exactly how much current is going through the circuit. With this information I can put the figures into an equation that will work out how much resistance that particular wire has. I chose to investigate length and thickness as they are both continuous as opposed to the type of wire which is -----. Once I have got the readings from the ammeter and voltmeter I can put the data into this equation.

Resistance (r) = voltage (v)

Current (i)

I am going to measure the amount of current which passes through six different thicknesses of nickel chrome.

Middle

Thickness

(SWG)

Thickness

(mm)

calculation

Average

(A)

20

0.90

(1.8 + 1.85 + 1.9) ÷ 3

1.85

22

0.71

(1.45 + 1.5 + 1.5) ÷ 3

1.48

24

0.56

(0.15 + 0.15 + 0.2) ÷ 3

1.17

26

0.45

(0.85 + 0.9 + 0.9) ÷ 3

0.88

28

0.37

(0.65 + 0.65 + 0.65) ÷ 3

0.65

30

0.31

(0.4 + 0.4 + 0.4) ÷ 3

0.4

To work out the resistance of each wire I am going to put in the average readings into the equation. The voltage was kept constant at 3volts so I’m going to divide 3 by each of the average readings.

 Thickness(SWG) Thickness(mm) Calculation Resistance(  ) 1dp 20 0.90 3 ÷ 1.85 1.6 22 0.71 3 ÷ 1.48 2 24 0.56 3 ÷ 1.17 2.6 26 0.45 3 ÷ 0.88 3.4 28 0.37 3 ÷ 0.65 4.6 30 0.31 3 ÷ 0.4 7.5

I have plotted a scatter graph of the results to see if there is a pattern. I am hoping that it will be inversely proportional where as the thickness in mm increases the resistance will decreases.

Length

 Length (cm) Result 1, amps (A) Result 2,amps (A) Result 3,amps (A) 10 1.5 1.5 1.5 20 0.85 0.85 0.85 30 0.6 0.6 0.6 40 0.45 0.45 0.45 50 0.4 0.4 0.4 60 0.3 0.3 0.3 70 0.25 0.25 0.25 80 0.225 0.225 0.225 90 0.2 0.2 0.2 100 0.15 0.15 0.15

Conclusion

The reason for the resistance to increases as the length increased is because the electrons have to travel further meaning there will be a lot more points where the electrons will be colliding with the ions. I can see that there the results increase at a curtain rate. I have worked out that the average resistance increase is about 1.8 ohms. When working out this calculation I dismissed the reading for 50cm as it was an anomaly.

Evaluation

I personally think that the experiment went very well. The experiment proved what I originally thought would happen. The resistance increased as the thickness of the wire decreased. My results were very good as I seem not to have any anomilious data and they all support my prediction. I think that my results are quite accurate; the only thing that could have been inaccurate was the length of the wire as we had to keep changing the wires over. Even though I made sure I was as accurate as possible the results could have been 6.6% inaccurate due to the plus or minus 1 factor in the measuring.

If I had more time to do the experiment I would have done some more repeat readings as there wasn’t enough time to do more than that three sets of results for each thickness of wire. I probably would change the length of wire is I got the chance to redo the experiment. I would make the wire longer, about 50cm or even 100cm. This will reduce the amount of possible inaccuracy as it would go down to 1% or 2%.

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. ## Investigation in resistance in wires

5 star(s)

Another change was adding a variable resistor; the change reduced the heating effect majorly by lowering the current in the circuit and helped to carry out fair test. I also decided that after each set of tests on each piece of wire I would turn off the power pack straight away while I get ready for the next set, e.g.

2. ## Physics Coursework Investigating Resistance of wires and its relationship to length.

However the results didn't change a great deal so the error bars would not be easy to draw on. Copper: Length (mm) Current (i) Voltage (v) 500 0.55 2.46 600 6.20 0.84 700 2.36 0.91 800 5.90 0.97 These results are not very reliable because the voltmeter wasn't working properly and the results were hard to read.

1. ## Investigating how thickness and length affect the resistance of a wire.

It is possible for a wire to suddenly snap and may come up, although this is very unlikely, it's best to stay aware of this factor and wear goggles. Fair Test In every investigation it's important to perform a fair test, if an investigation / experiment is not as fair

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

I will then need to take and record the readings from the two ammeters and voltmeters and I will need to keep the keep the amps to 0.3 to get the required reading to work out an average and compare it with my other results to ensure that the result isn't anomalous.

1. ## Resistance and Wires

The variable in the first experiment was the length, of test wire that is used in the circuit. The variable in the second part of the investigation was the diameter of 10cm of nickel-chrome wire. I chose these variables for this investigation because they can be manipulated in various ways as shown in the experiment.

2. ## Resistance of wires

for calculating electrical resistance, but still only applies to materials which comply with Ohm's Law (metals). Affecting Factors The four factors that affect the resistance of a wire are: * Material (the wire's material's construction and denseness affects the resistance of it, as, in this case, it depends how freely electrons can flow through it).

1. ## Resistance of wires.

Planning my investigation I intend to investigate the factors that determine the electrical resistance of Constantan wire. Constantan wire is so called because it is a special alloy of metals that does not alter its resistance very much when the temperature of the wire rises.

2. ## Objective: to investigate how the rate of resistance is affected by the different thicknesses ...

will not collide with the nuclei's frequently as there are not many, resulting to a decrease of the resistance of the wire. Four factors affecting the resistance in a circuit: 1. Length of Wire The longer the wire, the higher the resistance.

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