Motor effect

• What is the motor effect?

  A current-carrying wire in a magnetic field experiences a force
• Why does a current-carrying wire experience a force in a magnetic field?

  The magnetic fields of the wire and the external field interact
• At what angle must the wire be to the magnetic field to experience the full force?

  90 degrees
• What happens to the force if the wire is at a slight angle to the magnetic field?

  The wire feels slightly less force
• What happens to the force if the wire runs in the same direction as the magnetic field?

  The wire feels no force
• What is Fleming's left-hand rule used for?

  To determine the direction of the force on the wire
• How does Fleming's left-hand rule work?

  Thumb points to force, first finger to magnetic field, second finger to current
• If the magnetic field points downward and the current flows toward you, what direction is the force?

  To the right
• What is the equation to calculate the force on a current-carrying wire in a magnetic field?

  $F =$$BIL$
• What is the force on a 10 cm wire with a 5 A current in a 0.4 T magnetic field?

  0.2 N
• Why must the length of the wire be in meters when using the equation $F =$$BIL$?


  To ensure the units are consistent for the calculation
• What are the steps to use Fleming's left-hand rule?

  1. Point first finger in the direction of the magnetic field (north to south)
  2. Point second finger in the direction of the current
  3. Thumb points in the direction of the force
• How do you calculate the force on a wire in a magnetic field?

  1. Ensure all units are correct (length in meters)
  2. Use the equation $F =$$BIL$
  3. Plug in values for magnetic flux density (B), current (I), and length (L)
  4. Calculate the force (F) in newtons
• What is the unit of magnetic flux density?

  Tesla
• What is the unit of force in the equation $F =$$BIL$?


  Newton
• Why is the magnetic flux density referred to as "magnetic field strength"?

  It quantifies the strength of the magnetic field
• If the current in the wire is doubled, what happens to the force?

  The force doubles
• If the magnetic flux density is halved, what happens to the force?

  The force halves
• If the length of the wire is tripled, what happens to the force?

  The force triples
• How does the motor effect demonstrate the interaction between electricity and magnetism?

  It shows that a current-carrying wire in a magnetic field experiences a force due to the interaction of their magnetic fields
• What is the direction of the magnetic field between the poles of a horseshoe magnet?

  From north to south
• If the current in the wire is reversed, what happens to the direction of the force?

  The force reverses direction
• If the magnetic field direction is reversed, what happens to the direction of the force?

  The force reverses direction
• Why is it important to ensure the wire is at 90 degrees to the magnetic field when calculating the force?

  Because the force is maximized at 90 degrees
• What is the unit of current in the equation $F =$$BIL$?


  Ampere
• What is the unit of length in the equation $F =$$BIL$?


  Meters
• If the wire is 20 cm long, what length should be used in the equation $F =$$BIL$?


  0.2 meters
• Why is the motor effect important in practical applications?

  It is the principle behind electric motors
• How does the motor effect differ from electromagnetic induction?

  Motor effect involves force on a current-carrying wire, while induction involves generating current from a changing magnetic field
• What is the direction of the force if the current flows away from you and the magnetic field points downward?

  To the left
• If the wire is at 45 degrees to the magnetic field, what happens to the force?

  The force is slightly less than maximum
• Why is Fleming's left-hand rule specifically for the motor effect?

  It helps determine the direction of the force on a current-carrying wire in a magnetic field
• What is the direction of the current in Fleming's left-hand rule represented by?

  The second finger
• What is the direction of the magnetic field in Fleming's left-hand rule represented by?

  The first finger
• What is the direction of the force in Fleming's left-hand rule represented by?

  The thumb
• If the current is 3 A, the magnetic flux density is 0.5 T, and the wire length is 0.2 m, what is the force?

  0.3 N
• Why is the motor effect considered a fundamental principle in electromagnetism?

  It demonstrates the interaction between electric currents and magnetic fields
• How does the motor effect relate to the operation of electric motors?

  Electric motors use the motor effect to convert electrical energy into mechanical motion
• What is the direction of the force if the current flows toward you and the magnetic field points upward?

  To the left
• If the wire is at 180 degrees to the magnetic field, what happens to the force?

  The force is zero