Now we look at the forces we get in a coil of wire when it's in a magnetic field.
Youtube video, suitable whether of not you have the board with you.
See board images.
Tutorial guide for when you have the board with you.
Now here’s a strange board. Note the big black bit of metal in the middle, it’s a horseshoe magnet. The north pole is the end of the metal at the top, the south pole is at the bottom and there is a strong magnetic field between them. Now look at the coil, part of this goes through the strongest part of the magnetic field. When we pass a current through the coil it will turn into a magnet and the force created will push it to the side. You can see this by pressing the red button and holding it down. Note which way the coil is moving. Now flick the Reverse Polarity switch and press the red button again. You should see it move the other way. This idea of a force (push) being created by an electromagnet (coil)) in a magnetic field has many uses which we will see in a minute.
You can use your left hand to work out the direction of the force in this experiment. Straighten your thumb and first two fingers (these are called the index finger and middle finger). All three must be are at right angles to each other. Move your hand round so that your index finger is in line with the magnetic field, with the finger pointing towards the south pole. At the same time having your middle finger parallel to the wire with the end of this finger pointing in the direct the current is travelling (towards the negative side). Now your thumb is pointing in the direction of the force trying to move the wire.
If we increased the current, then the coil would move a greater distance marking it a crude ammeter, while it would be difficult to get an accurate reading here, this idea is used in all the panel ammeters you have been using!
Online search Fleming's Lefthand Rule. This will tell you how you can predict the direction of the force on the wire.
Some follow-up ideas to try...