Motor effect

• What is the motor effect?

  A current-carrying wire in a magnetic field experiences a force
• What happens when a current-carrying wire is placed between two magnets?

  The wire experiences a force due to magnetic field interaction
• What is required for a wire to experience the full force in a magnetic field?

  The wire must be at exactly 90 degrees to the magnetic field
• What happens if the wire is at a slight angle to the magnetic field?

  The wire will feel slightly less force
• What is the effect on the wire if it runs in the same direction as the magnetic field?

  The wire would feel no force at all
• What two directions do we need to know to find the direction of the force on the wire?

  The direction of the magnetic field and the current
• What is Fleming's left-hand rule used for?

  To determine the direction of the force on the wire
• How do you position your fingers according to Fleming's left-hand rule?

  Thumb up, first finger forward, second finger out
• What does the first finger represent in Fleming's left-hand rule?

  The direction of the magnetic field
• What does the second finger represent in Fleming's left-hand rule?

  The direction of the current in the wire
• What does the thumb represent in Fleming's left-hand rule?

  The direction of the force felt by the wire
• In the scenario with the horseshoe magnet, what is the orientation of the magnetic field?

  The magnetic field points downwards from north to south
• What happens when the power source is turned on in the horseshoe magnet scenario?

  The rails generate their own magnetic field
• How do you determine the direction of the force in the horseshoe magnet scenario?

  Use Fleming's left-hand rule
• What is the equation to calculate the strength of the force on the wire?

  $F =$$BIL$
• What does the variable 'F' represent in the equation $F =$$BIL$?


  Force measured in newtons
• What does the variable 'B' represent in the equation $F =$$BIL$?


  Magnetic flux density measured in teslas
• What does the variable 'I' represent in the equation $F =$$BIL$?


  Current measured in amperes
• What does the variable 'L' represent in the equation $F =$$BIL$?


  Length of the wire measured in meters
• If a wire is 10 cm long and carries a 5 amp current in a magnetic field of 0.4 teslas, what is the force experienced?

  0.2 newtons
• How do you convert the length of the wire from centimeters to meters?

  Divide by 100
• What is the first step to calculate the force using $F =$$BIL$?


  Ensure all figures are in the right units
• What are the key components of the motor effect?

  • Current-carrying wire
  • Magnetic field interaction
  • Force experienced by the wire
• What are the steps to apply Fleming's left-hand rule?

  1. Point thumb up (force direction)
  2. Point first finger forward (magnetic field direction)
  3. Point second finger out (current direction)
• What is the significance of the angle of the wire in a magnetic field?

  • 90 degrees: full force
  • Slight angle: less force
  • Same direction: no force
• What is the relationship between current, magnetic field strength, and wire length in calculating force?

  • Force is proportional to:
  • Current (I)
  • Magnetic flux density (B)
  • Length of wire (L)