There are many ways of visualizing it, but the simplest, most universally-applicable way is to think of the moving electrons and the force on them due to the Lorentz Force Law F=3DqVxB where x is a vector cross product. q is the electron's charge, V is the electron's velocity, and B is the magnetic field vector at the location of the electron. To determine the force and torque which one permanent magnet applies to another, you can either consider them both to be rings of moving charges and use the Lorentz approach or consider them to be magnetic dipoles and use the equations for the force and torque on a magnetic moment in a magnetic field. Sean On Wed, Mar 9, 2011 at 10:56 AM, Andrew Wood wrote: > Ive been doing some reading up about this and Im a little confused as to > whether its caused by an interaction between the magnetic field induced > in the rotor pushing against the magnietic field from the stator or > whether there is a thrust induced on the rotor itself just from the > having current flow through it. Reading about Flemings Left hand rule > suggests the latter but if that were so surely transformers and inductor > coils would move!? > > On 22/02/2011 12:50, Olin Lathrop wrote: >> Andrew Wood wrote: >>> What phenomenon is responsible for it becoming harder to turn? >> Magnetic forces from the current. =A0As current flows, the magnetic fiel= d >> produced by that current apposes the motion of the magnets in the other = part >> (rotor/stator) of the generator. >> >> > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .