Motor Effect

• What is the motor effect?

  A current carrying wire in a magnetic field experiences a force
• What happens when a wire is placed between the north and south poles of two magnets?

  The wire experiences a force due to magnetic field interaction
• At what angle does a wire experience the full force in a magnetic field?

  At exactly 90 degrees to the magnetic field
• What happens if the wire runs in the same direction as the magnetic field?

  It feels 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 rule do we use to determine the direction of the force on the wire?

  Fleming's left-hand rule
• 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 on the wire
• In the scenario with the horseshoe magnet, what happens when the power source is turned on?

  The rails generate a magnetic field and experience a force
• How do we determine the direction of the force in the horseshoe magnet scenario?

  Using Fleming's left-hand rule again
• What is the orientation of the magnetic field in the horseshoe magnet scenario?

  Pointing downwards from north to south
• What is the equation to calculate the strength of the force on the wire?

  f = b i l
• What does the variable 'f' represent in the equation f = b i l?

  Force measured in newtons
• What does the variable 'b' represent in the equation f = b i l?

  Magnetic flux density measured in teslas
• What does the variable 'i' represent in the equation f = b i l?

  Current measured in amperes
• What does the variable 'l' represent in the equation f = b i l?

  Length of the wire measured in meters
• How do you convert 10 centimeters to meters for the calculation?

  Divide by 100 to get 0.1 meters
• What is the force experienced by a wire with a 5 amp current in a 0.4 tesla magnetic field?

  0.2 newtons
• What are the steps to calculate the force on a wire in a magnetic field?

  1. Ensure all figures are in correct units
  2. Use the equation: $f =$$b i l$
  3. Plug in values for b, i, and l
  4. Calculate the force
• What are the key concepts of the motor effect?

  • Interaction of magnetic fields
  • Force on current-carrying wire
  • Importance of angle (90 degrees)
  • Use of Fleming's left-hand rule
  • Calculation of force using $f =$$b i l$