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    Hi all!

    I've been learning about the motor effect in GCSE physics.

    I've finally managed to grasp some understanding on how a commutator works, and how current in the coil is reversed twice at every turn (of 360 degrees) . However, in my book it says that "the current direction in the coil is reversed twice every turn - changing the direction of the magnetic forces".

    This bit I don't understand. Why do the magnetic forces produced by the fixed magnets need to change, if the current is reversed for each end of the coil doesn't the forces act in the same direction?

    Please help - I'm confused! :confused:
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    Do you see what would happen if the commutator didn't reverse the direction of the current every half turn?

    In order for the force always to be in the same direction from a stationary point of view, it has to be reversed every half revolution from the point of view of the rotor.
    That's all there is, probably it'd be easier to understand if you saw an actual demo.
 
 
 
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