• 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

# Resistance Wire Investigation.

Extracts from this document...

Introduction

Aim: To investigate the effects of a resistance wire in an electrical circuit.

Key Factors: The Key Factors in this experiment are

• Volts - the amount of batteries in the circuit
• Length - the length of resistance wire in the circuit
• Type - Different types of resistance wire made from materials e.g. copper or aluminum.
• Circuit - whether the resistance wire is in series or parallel
• Components - how many bulbs, switches or motors etc. are in the circuit.
• Thickness of the wire- How thick the wire is in mm
• Insulated or not- if there are any materials insulating the wire in the circuit.
• Shape of wire- if the wire is bent out of shape

I have chosen to do the length of the wire.

## Prediction

I Think that the longer the wire the more resistance in the circuit. I think that for a 20cm length of wire, the resistance will be double the length of a 10cm wire.

The longer the wire the longer it takes for the current to travel through. If I use a high voltage on a small piece of wire the wire will burn out due to a high current. The electrons passing through the circuit on their way around the circuit have to push their way through a lot of atoms. The atoms resist the passage of electrons through the wire.

The resistance is measured in units called ohms.

Middle

Plan:

I will put together the same circuit to that I used in the preliminary practical.

I will use the following equipment:

A power pack

An ammeter

A meter of resistance wire

Crocodile clips

Circuit wire

A meter ruler

A voltmeter

I will use a 4Volt power pack. One end will be permanently connected to one end of a meter length of wire. The other end will be connected via an ammeter in series to a crocodile clip, which can be connected at any point over the meter length of wire. I will attach the wire to the meter ruler so I am able to clip the crocodile clips on at different lengths. From the preliminary practical, the lengths are: 10cm, 20cm, 30cm, 40cm, 50cm, 60cm, 70cm, and 80cm.

Measurements will be taken on the ammeter when the crocodile clip is fixed at between 10cm and 80cm from the permanently connected end.

Each measurement will be taken 3 times and an average current reading calculated. I will then be able to work out the resistance using the equation V=I x R

The circuit will only be connected to the power pack for the duration of the test. The circuit will be disconnected at the end of the test.

To make this a fair test I am only going to change the length of wire, my key factor.

Conclusion

The results could be more accurate with the following changes:

We should allow more time for the ammeter to settle

The crocodile clip could be placed more precisely on each 10cm mark.

We could cut up the wire and clipped the wire on the ends. This would give a more accurate reading.

Looking at the graph of amps v length of wire it is possible to fit a smooth curve through the results. Also on the ohms v length of wire a straight line can be drawn between the points with very little scatter. From these two graphs I can assume that a reasonable conclusion can be drawn because the results are reasonably accurate.

To improve the accuracy of the experiment further, I could use a perfectly straight piece of wire and I could also use a pure piece of metal instead of an alloy because of the variations in the composition of alloys. I could also use better technology to measure the Resistance for example I could use a more accurate ammeter that gives a better reading to more decimal places.

I would then take several; possibly five readings, letting the wire cool down completely before reading the next result. This would make it more of a fair test, as there are a greater number of readings to take an average from. I would work out the averages and record them.

In the physics textbook by Jim Breithaupt unit B ‘resistance’ page 73 quotes in a summary that the resistance of a wire is proportional to its length.

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. ## Resistance of a Wire Investigation

This tells me that the voltage measures the amount of energy used up in getting each coulomb of charge through the wire. The units of volts are the same as joules per coulomb. Therefore, Ohms law says the more resistance means more energy used to pass through the wire.

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

The multi meters give their reading to three decimal places whereas the normal ammeters and volt meters only give reading to two decimal places. * I could have extended the investigation more by finding how the cross-section area (thickness), material in wire (e.g.

1. ## Resistance in a Wire Investigation

The length will be from 0cm-100cm going up in 20cm intervals. I will also use crocodile clips to connect the wire to the multimeter. When measuring resistance in the length of the wire the independent variable is the length of the wire and the dependant variable is the resistance.

2. ## Wire Resistence Practical

* Battery size * Voltmeter used * Ammeter used * Circuit set-up To ensure that the final experiment is thoroughly planned out and thought through, I will conduct 2 preliminary experiments. These experiments will mainly aid in deciding which current constant to use.

1. ## Construct and test an anemometer.

Once calibrated, I will be able to use a look-up table to convert voltage produced into wind speed. Calibration To calibrate the sensor, I will need to accurately record the rpm of the cups. When I have accurately recorded the rpm of the cups for certain potential differences, I will

2. ## Planning Experimental Procedures

I attempted to investigate the resistance of copper wire. The resistance was so small that if I were to see a difference in resistance then I would have to use very large amounts of copper wire. If I did use large amounts of copper wire then there would be a fire risk, and also copper wire is very expensive.

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