• 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

# My aim is to find out what affect a length of a wire has on its resistance. The resistance will be measured by finding out the current and the voltage travailing through a wire at variable lengths.

Extracts from this document...

Introduction

10B

## Planning

Aim

My aim is to find out what affect a length of a wire has on its resistance. The resistance will be measured by finding out the current and the voltage travailing through a wire at variable lengths. I shall use 11 different lengths of wire so that I have a good range of readings and will be able to plot a line of best-fit graph from the results. The lengths will range from 10 cm to 100 cm and will have a gap of 10 cm between each length of wire so that for example I will have one wire with a length of 10 cm and the next smallest length of wire as 20 cm. I shall measure the lengths in centimetres as I want the divisions between the results clear and I believe that it will be easier to ensure that the wire is a precise number of centimetres. I am starting at 10 cm, because any length below that may be unsafe.

## Background knowledge

Resistance is the opposition to the flow of electrons. As the electrons flow through the wire they bump into atoms. When they bump into an atom, the electron looses some energy and slows down.

Middle

• One possible risk is that if I put too much current through the wire the wire will become hot and I could burn my finger from the heat. Also it may affect the resistance of the wire or blow a fuse in the power supply.
•  Another risk is that if my resistance wire is too short a short circuit or similar danger may occur; therefore my smallest length of wire shall be 10 cm in order to eliminate this risk.

## Planned Method

1. Measure the wires width at different parts of the wire to check that it has a constant width
2. Set up the above circuit connecting the wire into the circuit using crocodile clips at 10 cms apart using a ruler.
3. Turn on the voltmeter and the ammeter and make sure that both have a positive reading.
4. Making sure that variable resistor is at the begging take the first reading on the ammeter and the volt meter and record these results
5. Now move the variable resistor along and take the new readings
6. Continue to move the variable resistor until you get at least ten readings

Conclusion

/tr>

## 30cms

 Current Voltage Resistance 0.07 0.20 2.857… 0.08 0.22 2075 0.09 0.25 2.777… 0.10 0.28 2.800 0.12 0.33 2.750 0.14 0.38 2.714… 0.16 0.47 2.937… 0.24 0.67 2.791… 0.34 0.94 2.764… 0.37 1.02 2.756…

40cms

 Current Voltage Resistance 0.06 0.28 4.666… 0.07 0.31 4.428… 0.08 0.33 4.125 0.10 0.36 3.600 0.11 0.43 2.727… 0.13 0.51 3.923… 0.17 0.67 3.941… 0.22 0.86 3.909… 0.28 1.12 4.000 0.31 1.27 4.096…

Resistance Calculation

Examples-

First set of equipment: Length of wire= 10cm, Voltmeter reading= 0.15V, Ammeter reading= 1.40A

Formula: Voltage= Resistance    0.15V = 0.11 Ohms (2d.p)

Current                          1.40A

Therefore the resistance of the wire was 0.11 Ohms, with the wire length at 10cm and using the first set of equipment.

Second set of equipment: Length of wire= 60cm, Voltmeter reading= 0.86V, Ammeter reading= 0.46A

Formula: Voltage= Resistance    0.86V = 1.87 Ohms (2d.p)

Current                          0.46A

Therefore the resistance of the wire was 1.87 Ohms, with the wire length at 60cm and using the second set of equipment.

Third set of equipment: Length of wire= 90cm, Voltmeter reading= 0.94V, Ammeter reading= 0.13A

Formula: Voltage= Resistance    0.94V = 7.62 Ohms (2d.p)

Current                          0.13A

Therefore the resistance of the wire was 7.62 Ohms, with the wire length at 90cm and using the third set of equipment.

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

The word atom is derived from the Greek word atom which means indivisible. The Greeks concluded that matter could be broken down into particles to small to be seen. These particles were called atoms Atoms are composed of three types of particles: protons, neutrons, and electron.

2. ## Aim: the aim for this experiment is to check if the length of a ...

> Wear goggles all the time. Ranges: o 10cm o 20cm o 30cm o 40cm o 50cm The difference between reliable and accurate data is that the reliable data will include a diagram with good results; it is not based on luck.

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

the constant variables such as different particle existing in atoms that has not been detected yet. This probability, however slight, must not be left out of the evaluation.

2. ## How does the length of a wire affect its resistance

Research and Preliminary experiment I firstly carried out a preliminary experiment, using three different sets of wires, to see whether they have different resistances, but also to familiarise myself with the experiment. Types of wire: * Copper wire * Nickel Chrome * Constantine Equipment used * Power pack * Ammeter

1. ## How does length and width affect resistance

It involves collisions between the free electrons and the fixed particles of the metal, other free electrons and impurities. These collisions convert some of the energy that the free electrons are carrying into heat. The unit of resistance is Ohms How can resistance be measured?

2. ## How Does the Shape of a Resistance Wire affect its resistance?

Read and record the ammeter and the voltmeter in the table. 4. Repeat steps 2 and 3 another four times, each time folding the wire. The first time you repeat the experiment, the wire should be folded just once, to double the thickness of the wire.

1. ## The Resistance of Lengths of Wire.

I will first test my circuit with no test wire, and just touch the crocodile clips together so that I can subtract the resistance of the circuit's wire. Fair Test: I will try to follow Ohm's Law: the resistance of a metal wire or a piece of carbon will stay the same as conditions are not changed e.g.

2. ## Find out how the length and width affect the resistance of a graphite track.

1a And substituting V into equation 2 we get: R2 = R1I 2I Cancelling the Is we get: R2 = R1 2 Or R2 is half of R1 This is part of a more general formula for finding resistance of uniform materials.

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