electric motors and loudspeakers

• how do electric motors work?

  • the forces act one up and one down so causes the coil to rotate
  • the spilt ring commutator reverses the current to keep the motor spinning the same direction
• how does a loudspeaker work?

  • an alternating current goes through the coil of wire attached to the base of the paper cone
  • the coil surrounds one pole of a permeant magnet so the current causes a force on the coil so the cones moves
  • when the current reverses the force acts in the opposite direction so the cone does the same
  • the variations of the current causes the cone to vibrate which causes sound waves.
  • the frequency of the sound wave is the same as the frequency of the alternating current
• split ring commuters allows the current to flow in the same direction