I believe that when more coils are added, the strength of the magnet will increase therefore it will be able to attract more paper clips. I believe this will happen because as more coils are wrapped around the core, the magnetic field gets stronger and stronger. For this investigation I will be changing the amount of coils to increase the magnetic fields strength. I will increase the amount of coils by 5 for every experiment. I will start with 5 coils of wire, then move onto 10, 15 etc up to 45.
I will be measuring the amount of paper clips picked up by the magnet in a chain. The main problem with using this method is that it is not particularly accurate and it can be very hard to attach the paper clips once you have reached a certain length. I will repeat each experiment three times so I can work out a clear average and also make sure that previous results are not flawed in some way.
The experiment could be affected by varying paperclip weights so to keep the experiment fair; I will only use paperclips of the same type. And I will the same amount of paperclips – I will use 25 paper clips as the maximum. The amount of current going through the insulated wire could also fluctuate so I will use a power pack that will keep the current the same throughout the experiment. Also I will use the same iron nail and make sure I have demagnetised it after each experiment.
To keep the experiment fair, I will do the following:
· Make sure all the paperclips are the same.
· Have the same amount of paperclips.
· Keep the current the same throughout.
· Always use the same Iron nail.
· Keep the coils equally spaced.
Prediction:
I think that the more current that goes through the wire, the greater the electromagnetic pull of the iron nail will be. Therefore it will attract more paperclips.
Method
I collected one iron nail and a metre of insulated wire, a power pack and 25 paper clips. I set up the apparatus by wrapping the wire around the iron nail 5 times. I then attached the ends of the wire to the power pack. When I turn the power on, the current flows through the wire and magnetises the nail. I then put the nail into the pile of paperclips to see how many I could pick up. To also keep this experiment fair, I will only put the head of the nail in contact with the nails. I repeated each experiment 3 times so I could get a clear average. To demagnetise the nail, I connected the electromagnet to the a.c current. The a.c current is used to cancel out the d.c current still in the electromagnet. By doing this. It ensures that there is not magnetism in the nail for the next experiment.
Conclusion
I have shown in my experiment that my prediction “ I think that the more current that goes through the wire, the greater the electromagnetic pull of the iron nail will be. Therefore it will attract more paperclips was correct.” My graph shows some anomalous results, this could be due to the fact that I may have not demagnetised the electromagnet properly. And I may have had an odd result in one of the experiments, which would have altered the average.
Evaluation
I could have made a different approach to this experiment. Instead of using paperclips as a form of measuring the strength of the electromagnet by using iron filings. With this experiment I would have measured how big the circles were that had been formed by the electromagnet. Another way of measuring the strength of the electromagnet is to use a Newton Meter to see how many Newton’s can be lifted. The trouble with this experiment is that the Newton meter will be suddenly released – this will make it hard to read what the actual weight was.
