GCSE Science
Doodle Science teaches you high school physics in a less boring way in almost no time!
Follow me: https://twitter.com/DoodleSci
You can support me at: https://patreon.com/doodlescience
Script:
When a current passes through a wire it produces a magnetic field. If you put this magnetic field in another magnetic field, it puts a force on the wire. This is known as the motor effect.
To determine the direction of the force you use a handy trick called Flemming's left hand rule. The way this works is by taking your left hand and making this shape with it. You then assign your first finger to the direction of the magnetic field, which is always north to south, your second finger to the direction of the current, and your thumb to the direction of the force.
For example, in this case, Flemming's left hand rule states that the force would act in this direction.
A simple electric motor works using this fact. It works by looping a coil of wire around to two electrical contacts inside a magnetic field. This causes one side of the wire to move up and the other part to move down, which causes the whole thing to spin. It is attached to something called a split ring commutator which is a clever way of swapping the contacts every half turn to keep it moving in the same direction. You can make the motor go faster by either increasing the current or by using a stronger magnetic field.
So next time you use your hair dryer, you’ll know something more about the way it spins.
References:
1. http://www.bbc.co.uk/education/subjects/zrkw2hv
2. CGP GCSE Physics AQA Revision Guide.
read more
