Resistance of a Wire
4 star(s)
Electromagnets - an investigation on electromagnets, our aim will be to find out what effects the strength of an electromagnet and how it affects it.
Extracts from this document...
Introduction
Electromagnets
Electromagnets are used frequently everyday around the world in many different devices. An electromagnet is just a piece of iron core wrapped with coiled, insulated wire. They are activated by the electrical current flowing against them through the coiled wire. There is a metal armature that is magnetically pulled on to the iron bar when the current flows through the wire that is wrapped around the magnet and switches on whatever component it is linked to and supposed to switch on.
We will be performing an investigation on electromagnets and our aim will be to find out what effects the strength of an electromagnet and how it affects it.
The Background
In 1820 Hans Oested discovered that a wire carrying a current produced a magnetic field around its self. He also found out that if the direction of current changes, then the magnetic field direction will also change now if the wire is coiled together into a solenoid, then the field will get compressed and therefore become much stronger than before.
Middle
The Method
- First I will get the iron core and wrap the insulated wire around it 40 times so that it looks like a solenoid.
- Then I will connect the wire ends to the transformer and ammeter.
- I will set the current to 1 amp for the start of the experiments and for the last experiment it will be set to 1 amp all the way through.
- We then switch on the power and the iron core becomes magnetised.
- Then we hold the electromagnet close to the pins that are laid on the table.
- As the pins are attracted and stuck onto the magnet we will count them and record them in a table
- I will then increase the current by 0.5 amps until I reach 4 amps, recording the results every time I increase it by the 0.5 amps.
- We will then do the experiment No. 2 keeping the current the same (set at 1 amp) and set the turns to 20
- I will attempt to pick up pins, record results and repeat for every time I add an extra 20 turns.
Conclusion
The Evaluation
At the end I think that the investigation has worked out quit well and we received the results that we expected. I predicted that the strength of a electromagnets increase when you either wrap more wire around it or increase the current flowing through it and after performing the investigation I have found that I was right all along.
The results were in fact adequate enough to bring us to a firm conclusion. But even though my prediction was right we still received results that were not quite expected. This is due to the errors that were made in recording the results. We did not record the results properly because there were either pins hanging off or linked together.
We can improve the investigation by performing each experiment five times rather than the three to make it even fairer. As well as being fair the investigation will gain us very accurate results to show. We could also improve the investigation by using various types of core and various conducting wire (different diameters). To detect the actual strength of the electromagnet I could have used a compass.
This student written piece of work is one of many that can be found in our GCSE Electricity and Magnetism section.
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