Electromagnets are made from coils like this. We can make an electromagnet stronger by:. Solid copper wire is better because it can usually carry more current. It is best to have a large amount of copper to keep the resistance down. It is also good to have a lot of turns to make better use of the available current. Copper has the lowest resistance at room temperature, so its a great choice. It's also easy to solder together and you can buy copper wire anywhere. It is very important to insulate the wire otherwise it will short out the turns and the magnet will be ineffective.
You get the most current from a battery when its fully charged. Also, its a good idea not to withdraw the current at too high a rate.
You have to find out the optimum discharge current to get the best battery life. Also, you have to optimize your magnet design, especially the coil, to match your battery. The above equation tells you for a given current and number of turns how much magnetic field you will get. Another famous law, called Ohms law, tells you the relationship between amps, volts and resistance.
Your coil should be made so it has a voltage drop equal to what your battery can put out at the best rate of discharge. A piece of copper has resistance which can be determined form the following formula. So Ampere's law tells you how much field you get for a given current and turns count. Ohms law tells you about the voltage drop at the current you want for a given resistance and the formula for resistance tells you the resistance of the wire that you choose.
Some of the copper wire needs to be exposed so that the battery can make a good electrical connection. Use a pair of wire strippers to remove a few centimeters of insulation from each end of the wire.
Neatly wrap the wire around the nail. The more wire you wrap around the nail, the stronger your electromagnet will be. Make certain that you leave enough of the wire unwound so that you can attach the battery.
When you wrap the wire around the nail, make certain that you wrap the wire all in one direction. You need to do this because the direction of a magnet field depends on the direction of the electric current creating it.
The movement of electric charges creates a magnetic field. If you could see the magnetic field around a wire that has electricity flowing through it, it would look like a series of circles around the wire. If an electric current is flowing directly towards you, the magnetic field created by it circles around the wire in a counter-clockwise direction. If the direction of the electric current is reversed, the magnetic field reverses also and circles the wire in a clockwise direction.
If you wrap some of the wire around the nail in one direction and some of the wire in the other direction, the magnetic fields from the different sections fight each other and cancel out, reducing the strength of your magnet. Connect and share knowledge within a single location that is structured and easy to search. Can an insulated wire be used to make a electromagnet?
Will there be any difference in strength of the magnet if I use an uninsulated wire instead? By uninsulated wire I mean this:. All current flow does produce a magnetic field after all, but it's impractical. Not all insulation is a rubbery or plastic material. The magnet wire which is typically used in things like transformer, motor, and electromagnet coils is insulated with a thin, hard laquer or enamel.
It's made to be very thin so you can squeeze as many turns as possible into the same volume. It could be but if so it is a dumb usage. The only reason that would work with an un-insulated wire is more 'by accident'. The accident in this case is that with an un-insulated wire the screw is shorting out the copper coil. But because copper has a much lower resistance and the screw is probbably not making very good contact, most of the current is still going through the copper and giving still a magnetic field.
Normally an insulated wire is used to make an electromagnet. The strength of electromagnet using insulated wire will be more than the one made with non insulated wire considering the batter size, wire thickness, number of turns, and the core remains the same. The reason is if the wire is non insulated then the electron may move straight through the core nail in your experiment rather than going in loop creating the more powerful magnetic field.
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