Electric Motors

• A current carrying coil of wire rotates in a magnetic field
• • Forces act on the two side arms of a coil which are carrying the current
  • As the coil is on a spindle, the forces act one up and one down, so it rotates
  • The split-ring commutator swaps the contact every half turn to keep the motor rotating in the same direction
  • The direction of a motor can be reversed by swapping the polarity of the dc supply or swapping the magnetic poles over