Motor Effect Flashcards
What is the motor effect?
A current carrying wire in the presence of a magnetic field will experience a force
Why will a current carrying wire experience a force in the presence of a magnetic field.
As we know, a current carrying wire will create its own magnetic field around the wire, so this magnetic field will interact with the other magnetic field and therefore a force will be produced trying to push the wire out of the field.
How do we get the “full force” on the wire?
The wire has to be exactly 90 degrees to the magnetic field. The force reduces as the angle goes down and will become zero as the wire becomes parallel to the magnetic field.
Which rule can we use to find the direction of the force?
Fleming’s left hand rule. The thumb tells us the force, the index finger the direction of the magnetic field from north to south and the middle finger the direction of the current
What other type of magnet can the motor effect occur and explain?
Between the 2 poles of a horseshoe magnet. Between, we will have 3 metal rails in which a current can flow. The two rails on the side are fixed but the one one top is free to move. We can find the direction of the force using Fleming’s left hand rule. Remember the two rails are fixed so you need to apply the rule to the free moving rail.
