electric motor

• What should you be able to describe by the end of the video?

  How an electric motor works
• What is the motor effect?

  A force on a current-carrying conductor in a magnetic field
• What rule helps determine the direction of the force in the motor effect?

  Fleming's left hand rule
• What happens to a loop of wire carrying current in a magnetic field?

  • Experiences a force on both sides
  • Left side force acts upwards
  • Right side force acts downwards
  • Causes clockwise rotation
• What happens to the loop when it rotates beyond 90 degrees?

  The forces push the loop back to 90 degrees
• How can the problem of the loop stopping at 90 degrees be solved?

  By switching the direction of the current
• What device is used to switch the direction of the current in an electric motor?

  Split ring commutator
• What is the function of the split ring commutator?

  • Switches the direction of the current
  • Connected to conducting brushes
  • Allows continuous rotation of the motor
• What happens to the current for a tiny fraction of a second during motor operation?

  The current switches direction
• What keeps the wire turning after the current switches direction?

  Momentum
• How does switching the direction of the current affect the forces on the loop?

  Left side force acts upwards, right side downwards
• Where can students find questions on electric motors?

  • In the vision workbook
  • By clicking on the provided link