7.2.2 Electric Motors

• What is an electric motor used for?

  Converts electrical to mechanical energy
• The motor effect occurs when a current-carrying conductor is placed in a magnetic field.

  True
• The force in the motor effect is directly proportional to the current
• Steps explaining the motor effect

  1️⃣ Current flows through conductor

  2️⃣ Magnetic field interacts

  3️⃣ Force exerted on conductor

  4️⃣ Conductor moves
• The force in the motor effect is zero when the angle between the conductor and the magnetic field is parallel
• Fleming's left-hand rule helps determine the direction of the force on a current-carrying conductor in a magnetic field.


  True
• In Fleming's left-hand rule, the thumb points in the direction of the force
• In Fleming's left-hand rule, what does the index finger indicate?

  Magnetic field
• What is the motor effect?

  Force on a conductor
• The current in the conductor is directly proportional to the motor effect force.
• The rotor in an electric motor is a coil of wire
• What does Fleming's left-hand rule help determine?

  Direction of force
• The force in the motor effect is greatest when the conductor is parallel to the magnetic field.

  False
• Which finger in Fleming's left-hand rule points in the direction of the magnetic field?

  Index finger
• What is the angle between a conductor and a magnetic field when the force is greatest?

  90°
• The middle finger in Fleming's left-hand rule points in the direction of the current
• The strength of the motor effect force is directly proportional to the current in the conductor.


  True
• The length of the conductor in a magnetic field is directly proportional to the motor effect force.
• The motor effect force is greatest when the conductor is parallel to the magnetic field.

  False
• Why does a current-carrying conductor experience a force in a magnetic field?

  Interacting magnetic fields
• What happens to the motor effect force if the magnetic field strength decreases?

  Decreases
• What is used to create the magnetic field in a DC electric motor?

  Permanent magnet
• The commutator in a DC electric motor ensures continuous rotation by reversing the current direction.


  True
• What is the term for the force experienced by a current-carrying conductor in a magnetic field?

  Motor effect
• Match the component of an electric motor with its description:

  Power Source ↔️ Requires electrical current

  Magnetic Field ↔️ Creates magnetic force

  Rotor ↔️ Rotates when current flows

  Commutator ↔️ Reverses current direction
• What type of energy does an electric motor convert into mechanical energy?

  Electrical energy
• What are the four key features of an electric motor?

  Power source, magnetic field, rotor, commutator
• What is the motor effect?

  Force on a conductor
• What happens to the motor effect force if the magnetic field strength increases?

  Increases
• What force is experienced by a current-carrying conductor in a magnetic field?

  Motor effect
• The force is greatest when the conductor is perpendicular to the magnetic field.


  True
• What is the motor effect?

  Force on current-carrying conductor
• What happens to the motor effect force if the magnetic field strength increases?

  Increases
• Arrange the steps shown in the flowchart for Fleming's left-hand rule:

  1️⃣ Current flowing into page

  2️⃣ Magnetic field from left to right

  3️⃣ Force upwards
• The motor effect force is directly proportional to the current in the conductor.
• Match the component of a DC electric motor with its description:

  Power Source ↔️ Provides electrical current

  Magnetic Field ↔️ Creates magnetic field

  Rotor ↔️ Coil of wire that rotates

  Commutator ↔️ Reverses current direction
• The rotor in a DC electric motor is a coil of wire that carries the current and rotates.
• Arrange the steps in how an electric motor generates motion:

  1️⃣ Current-carrying conductor placed in magnetic field

  2️⃣ Conductor experiences a force

  3️⃣ Rotor begins to rotate
• The conductor in an electric motor that carries the current is called the rotor.
• The commutator in an electric motor ensures continuous rotation by reversing the current direction.


  True