Will increasing current in an electromagnet increase the power of the electromagnet?

Electromagnetism experiment:

Introduction:

I start the introduction with a question: Will increasing current in an electromagnet increase the power of the electromagnet?

The electromagnet we will be making is a very primitive one compared to that of the complexity of modern electromagnets found in machinery, but the way it works is almost identical. Electromagnetic technology is extremely complex and because it is an electromagnet, the higher the current, the stronger it becomes, and with this an electromagnet can become incomprehensively strong. Such an example is that used in theme park rides to stop moving parts etc. these electromagnets are in fact so strong that when uncovered, if you were to stand with a spanner in your hand 10 metres away, it would pull the spanner out of your hand along with the rest of your arm! To understand fully how an electromagnet works read on…

Background information:

When an insulated wire is wrapped around some form of iron, nickel or cobalt core, whether it be a nail or a u-shaped core, and then attached to a power supply it creates an electromagnet capable of picking anything from the size of a paperclip right up to anything as big as a car and bigger! Obviously such a primitive electromagnet would not be able to lift a car but a more advanced one would have no problem lifting a car. When the power supply is cut off the items picked up will fall off. This is because the current creates a magnetic field and this magnetic field is lost when it is turned off.

When a current channels through an electromagnet a magnetic field is produced. This field is built up in a series of concentric rings. The diagram below shows a cross-section of a wire’s magnetic field. As you come further away from the wire the field weakens and spreads further apart from each ring.

There are four main factors that affect the strength and size of this field:

Current/voltage

Number of coils

Size and shape of core

Material of core (iron being the strongest)

For example: two coils wrapped around the iron core would induce twice the strength of one coil. ...

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There are four main factors that affect the strength and size of this field:

Current/voltage

Number of coils

Size and shape of core

Material of core (iron being the strongest)

For example: two coils wrapped around the iron core would induce twice the strength of one coil. By this I mean that each coil will have twice the strength of one coil on it’s own. Below shows a single coil’s magnetic field. When two are present these rings become double the size creating a considerably larger and stronger field.

Magnets are formed when certain substances (iron, nickel and cobalt) cool. Normally when a non-magnetic substance crystallises the atoms point in random directions. Now because of the properties of the aforementioned substances their atoms point in similar directions at each end of the magnet. These are called domains. This is because of the nature of the earth’s gravitational field. Each side of the magnet’s atoms, point in opposite directions. Each domain is known as either the south or north pole. Each end of the magnet is where the strongest part of the magnetic field coincides.

The experiment in hand is simple. A piece of wire will be wrapped around an iron nail or some form of iron-based core where each end of the wire is attached to a circuit consisting of a power source and an ammeter. Our group will be testing the power of the magnet varying the power of the current around the circuit. We will be testing the strength from 0 to 5 amps.

My prediction is that when the current is increased in turn so does the strength of the electromagnet. I believe this because an electromagnet needs an electrical input in order to create a magnet, so logically if that electrical input is increased then it becomes stronger.

The aim of this project is to test the power of an electromagnet when the current is increased or decreased.

Preliminary experiment

The initial experiment is just to test the strength by seeing how many nails are picked up at varying strength of current. We will also be testing the strength when the amount of coils are increased or decreased.

Apparatus:

Crocodile clip x 2

Red insulated wire x 2

Black insulated wire x 1

Ammeter

U-shaped iron core

1: An electrical wire will be coiled around a soft-iron core 30 times.

2: Crocodile clips will be connected to yellow connecting wires at each end.

3: These together with the ammeter will be connected up to the power supply as shown in the circuit diagram.

4: A fixed amount of nails will be poured over the electromagnet with the power switched on

5: The power will be turned off. All of the iron filings that drop off will be weighed.

I will vary only the current in this experiment. All other factors will be kept constant. I will measure the amount of iron filings at 1,2,3,4 & 5 amps. I will repeat each experiment three times for accuracy.

Safety Precautions

We will make sure that there is no bare insulation or any water near any electrical equipment to prevent electrical faults and dangers

I might need to repeat some results that show no correlation to the other results, if they are drastically wrong.

Factors Affecting The Experiment:

1:Current-This will change in one experiment. This will be kept constant by observing the ammeter and correcting any fluctuations on the D.C power pack.

2: Magnetic strength of the Soft-Iron Core. This will affect the power of the electromagnet. It will be kept constant by using the same soft-iron core.

3: The way in which the wire is coiled. If the coils are coiled towards end, then one end will be more powerful than the other, and affect the results. I will try to keep the shape of the coils uniform.

4:The way in which, the nails are shaken. The harder the magnet is shaken, then the more nails will be dropped, and the more the results will change. This will be tried to control, making sure to only shake off the ones that are very loose.

Results

Analysis

My results clearly show a rise in power of the magnet as the amps increase. This can only mean that an increase in current increases the power of the magnet. This is because when the current goes through the wires it creates a magnet. This is done by magnetising the substance’s core. In it’s core there are domains of which it’s electrons are aligned in opposite directions to create a north and south pole. The input of current creates an output of magnetism that increases as the input is increased. This is not cumulative and needs a constant input to perform and maintain the process. Consequently, the more put in the more that comes out so to speak.

I believe that although there were slight imperfections to do with fair testing my results were relatively constant with no really odd results. There is also a possibility that the nails after the first time were magneticly charged and so were slightly easier to pick up which could explain the increase in nails picked up each attempt.

We did have problems at first with our first magnet because we put a current through the wires which was too large and so our first was destroyed. Because of this our first results were scrapped. In future we know not to put more than 6 amps into the wiring as it does not manage very well above that.

The current was also very hard to put up to exactly 1 amp or 2 amps etc, but this difference was minute, and was likely not to have made much of a difference, if any.

All in all though I think our experiment was successful and was reliable enough to compare my prediction with. Had my prediction been wrong then it would have either meant that the experiment had not been done properly or that my research was incorrect.