Electrical Machines (Part-5)

Which type of motor is commonly used in printers and CNC machines for precise movement?

A Stepper motor
B Induction motor
C DC motor
D Synchronous motor

What is the primary benefit of a brushless DC motor over a brushed motor?

A Higher speed
B More torque
C Lower maintenance
D Increased efficiency

What is the key characteristic of a stepper motor?

A Variable torque
B Precision control
C High speed
D Continuous rotation

What does “back EMF” in a DC motor refer to?

A Torque increase
B Speed reduction
C Voltage that accelerates the motor
D Voltage that opposes current

Which component in a brushless DC motor replaces the commutator in a brushed motor?

A Stator
B Controller
C Brushes
D Rotor

What is the main advantage of using a permanent magnet in a motor?

A Lower cost
B Better cooling
C Higher efficiency
D Increased weight

What is the primary characteristic of a brushless motor?

A Reduced maintenance
B Increased heating
C High torque at low speeds
D Higher power consumption

In a stepper motor, what determines the angle of movement?

A Voltage frequency
B Current supply
C Magnetic field strength
D Pulse input

What is the primary function of a controller in a brushless DC motor?

A Monitor torque
B Provide power
C Regulate speed
D Reverse current

Which of the following is true for a stepper motorโ€™s operation?

A Has no torque at startup
B Moves in discrete steps
C Operates continuously at high speed
D Requires brushes for operation

What is one of the most common uses of a brushless DC motor?

A High-power motors
B Household appliances
C Electric vehicles
D Cooling fans

In a stepper motor, what happens if the motor is driven at too high a speed?

A It stalls or loses steps
B It increases torque
C It becomes more accurate
D It reduces efficiency

What is the purpose of the rotor in a brushless motor?

A To produce mechanical output
B To control speed
C To generate magnetic field
D To carry the current

What is the typical advantage of a stepper motor compared to a DC motor?

A More torque
B Higher efficiency
C Precise positioning
D Faster speed

How does a brushless DC motor reduce maintenance?

A By eliminating friction
B By reducing the operating speed
C By reducing torque
D By using a simpler controller