Motors and Magnetic Forces

Motors and Generators > Motors and Magnetic Forces

Motors use the effect of forces on current-carrying conductors in magnetic fields

Students learn to:

• discuss the effect on the magnitude of the force on a current-carrying conductor of variations in:
  • the strength of the magnetic field in which it is located
  • the magnitude of the current in the conductor
  • the length of the conductor in the external magnetic field
  • the angle between the direction of the external magnetic field and the direction of the length of the conductor
• describe qualitatively and quantitatively the force between long parallel current-carrying conductors:
• define torque as the turning moment of a force using:
• identify that the motor effect is due to the force acting on a current-carrying conductor in a magnetic field
• describe the forces experienced by a current-carrying loop in a magnetic field and describe the net result of the forces
• describe the main features of a DC electric motor and the role of each feature
• identify that the required magnetic fields in DC motors can be produced either by current-carrying coils or permanent magnets

Students:

• solve problems using:
• perform a first-hand investigation to demonstrate the motor effect
• solve problems and analyse information about the force on current-carrying conductors in magnetic fields using:
• solve problems and analyse information about simple motors using:
• identify data sources, gather and process information to qualitatively describe the application of the motor effect in:
  • the galvanometer
  • the loudspeaker