hi, i am to take my triple science Physics GCSE exam and i am really confused with electro-magnets.
What is EM induction, text books on the on this confuse me, what is Flux cutting and why do u need a split ring commutator in motors???
Any help would be nice!
thanx a bunch, i understand it now!!
i remember this one;
basically when a conductor crosses lines of a magnetic field it produces an electromotive force in the wire and can produce a current in it. it must cut the lines of the magnetic field/ magnetic flux and not go alongside them, it has to be at right angles. -the size of the current increases if you move the conductor accrose these lines more quickly or increase the strength of the magnet. just think- electromagnetic induction-you induce a current by putting a condutor of electricity accross a magnetic field.
onto motors- the motor effect is producing motion by passing a wire already carrying a current, accross magnetic field lines. i always think 'motor' as in inducing motion of the wire. in motors you need a split ring commutator because -if you have a picture of one there i'll expain or draw it as i explain-
you have a c shaped magnet with north on the left and south on the right, with a coil in the middle attatched to a power supply with the positive on the right. this means the left side of the coil eperiences a force -an electromotive force. so begins o move. to the right . howvere when it reaches a vertical position it is cuttin no lines of flux( field lines) but because of its inertia which is its resistance to change its motion it overshoots the vertical and the commutators switch sides reversing the current. this should be all you know for gcse and don';t worry too much hope that helps!!!
think i was a bit late then!! lol