Function

Particularly the electromagnetism is frequently inserted into the automobile. No power relay or inductive pickup would function without it. This is true also, e.g., for the Reed switch. Besides, the most important applications of the magnetism are not even yet mentioned: the generator and all electric motors, among them of course the starter and the solenoid.

How it works

The test shown on top displays it. One part has to move and the other stands still. If one of them is a magnet and the other a metal, energy spreads by magnetism. An example of this is the speedometer in older vehicles. Here the magnet turns and helps to pull by invisible forces the aluminium drum.

In the test on top it is the electric conductor which is pulled through the magnetic field. At its ends a tension can be taken off by sensitive metering gauges. If we rolled up the wire in several layers in the form of a coil, we could measure the tension already with less sensitive measuring instruments.

But magnetism does not only function in this direction. If we put, e.g., power on the wire, it moves. If we change the tension in each case in the terminator point (dead centre) of the movement, we receive an electric swing. If we turn the axis, we can build from it an electric motor.

Important

In the true test case, the pointer never stops in its end positions. As soon as we stop with the movement, the tension goes to zero, also in the end positions. The faster you perform the movement, the greater the induced voltage.