MOTOR EFFECT

    Cards (18)

    • Produced by current in wire
      Magnetic field
    • Strength of magnetic field
      Determines by current magnitude and distance from wire
    • Solenoid
      Coil of wire creating a strong magnetic field when current passes through
    • Magnetic field in solenoid
      Strong and uniform
    • Electromagnet
      Solenoid with added iron core for increased magnetic field strength
    • Motor effect
      Force between magnetic field and current-carrying conductor in the field
    • Fleming's Left-Hand Rule
      Rule to determine force direction in motor effect
    • Forefinger in rule

      Points in direction of magnetic field
    • Second finger in rule

      Points in direction of current flow in conductor
    • Factors affecting force on wire
      Current magnitude and magnetic field strength
    • Force reversal in wire
      Force direction reverses with current direction change
    • Force increase in wire
      Force strength increases with current strength increase
    • Criteria for force equation
      Conductor must be at right angles to magnetic field
    • Unit for magnetic flux density
      Tesla, T
    • Electric motor operation
      Coil in magnetic field experiences rotational forces
    • Loudspeakers use of motor effect
      Convert current variations into audible sound pressure variations
    • Loudspeaker operation

      Wire on cone vibrates in magnetic field, producing sound
    • Pitch change in loudspeaker
      Altering frequency of a.c current changes cone vibration frequency
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