#1
What is the purpose of a contactor in motor control?
To control the starting and stopping of the motor
ExplanationA contactor is used to control the starting and stopping of a motor.
#2
What is the function of a motor starter?
To provide power to the motor
ExplanationThe function of a motor starter is to provide power to the motor.
#3
What is the primary purpose of a motor overload relay?
To protect the motor against overheating
ExplanationThe primary purpose of a motor overload relay is to protect the motor against overheating.
#4
In a three-phase induction motor, which component is responsible for generating the rotating magnetic field?
Stator
ExplanationIn a three-phase induction motor, the stator is responsible for generating the rotating magnetic field.
#5
What is the function of a motor capacitor?
To provide starting torque in single-phase induction motors
ExplanationThe function of a motor capacitor is to provide starting torque in single-phase induction motors.
#6
Which of the following devices is used to control the speed of an induction motor?
Inverter
ExplanationInverter is used to control the speed of an induction motor.
#7
What component is used to start a single-phase induction motor?
Start capacitor
ExplanationA start capacitor is used to start a single-phase induction motor.
#8
Which of the following is NOT a type of DC motor?
Synchronous motor
ExplanationSynchronous motor is not a type of DC motor.
#9
What is the primary function of a soft starter in motor control?
To reduce mechanical stress during motor starting
ExplanationA soft starter's primary function is to reduce mechanical stress during motor starting.
#10
What is the role of a centrifugal switch in a single-phase induction motor?
To switch the starting winding out of the circuit
ExplanationThe role of a centrifugal switch in a single-phase induction motor is to switch the starting winding out of the circuit.
#11
Which of the following statements is true about a servo motor?
It is a closed-loop system
ExplanationA servo motor operates as a closed-loop system.
#12
Which of the following motor starting methods provides the highest starting torque?
Direct-on-line (DOL) starting
ExplanationDirect-on-line (DOL) starting provides the highest starting torque.
#13
Which motor starting method is preferred for large induction motors to reduce starting current?
Variable frequency drive (VFD) starting
ExplanationVariable frequency drive (VFD) starting is preferred for large induction motors to reduce starting current.
#14
Which of the following statements is true about a brushless DC motor (BLDC)?
It is more efficient and has a longer lifespan compared to brushed DC motors
ExplanationA brushless DC motor (BLDC) is more efficient and has a longer lifespan compared to brushed DC motors.
#15
What is the purpose of a variable frequency drive (VFD) in motor control?
To regulate motor speed by varying the frequency of the supplied voltage
ExplanationThe purpose of a variable frequency drive (VFD) in motor control is to regulate motor speed by varying the frequency of the supplied voltage.