The more coils used in the electromagnet, the stronger the magnet is. If there is one coil, and another is added then two coils have twice the strength of one. When there is more current passing, there will be more wire or a more magnetised core.
As the wire has no poles for being a magnet, the direction of the field is determined by ‘the right hand rule’ that which determines the direction of the field by looking at the direction of the current. If the current is flowing vertically upwards, the field is anti-clockwise, and if the current is flowing downwards, the field is going clockwise. If someone closes the right hand, the thumb is the direction of the current, and the fingers indicate the direction of the field, going round in a circle. This magnetic field magnetizes the metal and the metal becomes a magnet. This is started of with electricity, therefore the magnet is a called an electromagnet.
Henal Rajendra Patel
CENTRE NUMBER: 14625
CANDIDATE NUMBER: 0127
APPARATUS:
- Insulated Wire
- Iron nail
- 4 x Batteries
- Ammeter
- Iron filings
- Weighing Balance
- Connecting wires
- Variable resistor
- Goggles
- Paper
DIAGRAM:
Henal Rajendra Patel
CENTRE NUMBER: 14625
CANDIDATE NUMBER: 0127
PLAN:
- Collect all equipment needed for the experiment.
- Wrap the insulated wire round the iron nail 50 times.
- Connect the Batteries, Variable resistor and Ammeter.
- Then use the crocodile clips to connect each end of the insulated wire together, to form a flowing current.
- Make sure the current is steady at 0.2 amps all through the experiment.
- Pour some iron filings on a piece of paper, and then use the iron nail to pick up the iron filings.
- Disconnect the power after a while, and weigh the iron nail with the iron filings on it.
- Repeat the experiment till there are 10 turns on the nail. Each time I repeat the experiment take away 5 turns from the iron nail till I get to 10 turns on the nail.
- I will also repeat the whole experiment once more for fairness.
FAIRNESS:
To keep my experiment fair, I will use the same iron nail through the experiment and the second repeated experiment.
I will make sure the current is steady at 0.2 amps all through the experiments. I will also try and use the same amount of iron filings,
and use the same amount of insulated wire.
I will use the same batteries, variable resistor and ammeter throughout both experiments to insure fair results.
I will also keep my experiment fair because I feel that the more fairly I keep it the more accurate my results will be.
SAFETY:
To keep my experiment safe I will wear goggles when handling iron filings, also making sure the iron filings are not near my eyes or mouth.
I will also make sure there is not any water or bare insulation near any electrical equipment to prevent danger of electrocution.
Henal Rajendra Patel
CENTRE NUMBER: 14625
CANDIDATE NUMBER: 0127
‘RESULT TABLE FOR THE 1ST EXPERIMENT’
‘RESULT TABLE FOR THE 2nd EXPERIMENT’
Henal Rajendra Patel
CENTRE NUMBER: 14625
CANDIDATE NUMBER: 0127
CONCLUSION & ANALYSIS:
At the end of my experiments I found that when the number of turns decreased the less iron filings would be picked up. This is due to most of the magnetism being lost. The more coils used in the electromagnet, the stronger the magnet is.
The electric current along the wire creates a magnetic field around wire. The fields are in shape of a series of concentric rings.
A magnetic field is a region where magnetic materials such as iron and steel and also wires carrying currents experience force acting on them.
My results turned out quite fair and reasonable, although in my first experiment I did get one anomalous result.
The prediction I made earlier was correct I did find that fewer turns on the electromagnet would lead to less iron filings being picked up, this is exactly what happened in my experiment.
The number of coils around an electromagnet is not proportional to the electromagnetic strength. In my graph it shows that the number of coils are not proportional to the strength of the electromagnet, I found that this happened due to me getting anomalous result in my experiment.
When more coils are in contact with the core, more area of interaction is available, allowing more of the area to be magnetised quicker than if the area is smaller. If there is more area, the magnetic area will become stronger.
Henal Rajendra Patel
CENTRE NUMBER: 14625
CANDIDATE NUMBER: 0127
EVALUATION:
Generally I felt my experiment went well, I felt there could have been more accuracy in my experiment. I felt when weighing the electromagnet I could have zeroed the weighing balance before weighing before and after each experiment, which could have made my results fairer. Although I did feel it was a reasonably accurate experiment, and I think that if I repeated the experiment I would get similar results. I feel that I may have got the anomalous results from inaccurate measuring with the iron filings, because when I used iron filings I found that I had inaccurate amounts of iron filings, as when I shake of the iron filings not all of them fell of.
Reviewing the method I used I feel that it was suitable, however, I could have improved it by making more accurate measuring for the electromagnet.
If I wanted to make my experiment fairer I think I would repeat the experiment more than once. I could also have made a regular check on the ammeter to check the current was running at 0.2 amps, I think the current passing at different rates caused the anomalous result.
To extend the investigation I could have tried varying how tight the coils of wire are wrapped around the electromagnet or another factor, keeping the current constant, then another variable and comparing the results of varying those others. I could also have tried using paper clips instead of iron filings to see if different results were given.
Overall, I am happy about how my experiment turned out and the results I got.
Henal Rajendra Patel
CENTRE NUMBER: 14625
CANDIDATE NUMBER: 0127
BIBLIOGRAPHY
Physics for you Keith Johnson
Physics first George Bethall
David Coppock
CGP GCSE Double award Science Physics
The revision guide
GCSE Physics Second edition Tom Duncan
The Internet:
G C S E BBC revision bite size – www.bbc.co.uk/schools/gcsebitesize/
Henal Rajendra Patel
CENTRE NUMBER: 14625
CANDIDATE NUMBER: 0127
AVERAGE TABLE
This table shows the average mass of both experiments.
