Electric Motors and Generators

What is the purpose of the commutator in an electric motor?

• To change the direction of the current flowing in the armature

• To generate electrical energy

• To regulate the speed of the motor

• To provide a mechanical connection between the rotor and stator

What is the function of the stator in an electric motor?

• To create a magnetic field that interacts with the rotor
• To change the direction of the current flowing in the armature
• To store electrical energy temporarily
• To convert electrical energy into mechanical energy

What is the most common type of electric motor?

• AC motor
• DC motor
• Stepper motor
• Hybrid motor

What determines the speed of an electric motor?

• The frequency of the power supply
• The number of poles in the stator
• The size of the motor
• The voltage of the power supply

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

• To deliver electrical power to the armature
• To regulate the speed of the motor
• To provide a mechanical connection between the rotor and stator
• To create a magnetic field in the stator

What is the difference between a synchronous and an asynchronous motor?

• A synchronous motor operates at a constant speed, while an asynchronous motor has a speed that varies with the load
• A synchronous motor operates only on DC, while an asynchronous motor operates on AC
• A synchronous motor does not have a rotor, while an asynchronous motor does
• A synchronous motor is more efficient than an asynchronous motor

Which type of energy does an electric motor convert into mechanical energy?

• Electrical energy
• Light energy
• Sound energy
• Chemical energy

What is the purpose of the commutator in an electric motor?

• To reverse the direction of current flow in the armature
• To create the magnetic field in the stator
• To convert AC power to DC power
• To regulate the speed of the motor

What is the purpose of the magnetic field in an electric motor?

• To provide force for the rotation of the armature
• To transfer electricity from the power source to the armature
• To control the speed of the motor
• To generate heat

Which device can be driven by an electric motor?

• bicycle
• cooking pan
• toilet brush
• umbrella