141 S13 DC Motors 2

What is the function of the commutator in a DC motor?

• A) To provide one of the magnetic fields
• B) To rotate the armature
• C) To reverse the direction of current
• D) To generate electrical energy

What material are the brushes of a DC motor made of?

• A) Copper
• B) Aluminum
• C) Carbon
• D) Iron

Why are carbon brushes used in a DC motor?

• A) Because they are hard
• B) Because they are an insulator
• C) Because they are a conductor
• D) Because they overheat easily

What is the function of the armature windings in a DC motor?

• A) To provide one of the magnetic fields
• B) To generate electrical energy
• C) To rotate and provide mechanical energy
• D) To connect to the commutator

What is the purpose of the segments and insulators in the commutator of a DC motor?

• A) To provide one of the magnetic fields
• B) To rotate the armature
• C) To reverse the direction of current
• D) To generate electrical energy

How is the connection to the load made in a DC motor?

• A) Through the commutator
• B) Through the brushes
• C) Through the field windings
• D) Through the rotor

What happens when the armature coil in a DC motor moves through the plane perpendicular to the magnetic field?

• A) The torque on the motor reverses its direction
• B) The armature generates electrical energy
• C) The commutator reverses the direction of current
• D) The brushes become worn down

What is the purpose of the load in a DC motor?

• A) To generate electrical energy
• B) To provide a magnetic field
• C) To provide a mechanical load for the motor to work against
• D) To connect to the field windings

What type of supply is produced as the armature windings rotate within the magnetic field of a DC motor?

• A) A DC supply
• B) An AC supply
• C) A mechanical supply
• D) A hydraulic supply

What is the purpose of the carbon brushes in a DC motor?

• A) To provide a mechanical load
• B) To generate electrical energy
• C) To connect to the load
• D) To supply current to the armature