ENG6034 Motor Drive Training Quiz

What does MMF (Magnetomotive Force) primarily do in an electric motor?

• It generates the magnetic field that drives the rotor

• It produces back EMF to oppose rotation

• It determines the resistance of the stator windings
  

• It causes the motor to overheat during high load

What happens to CEMF as the motor speed increases?

• CEMF increases with speed

• CEMF only exists at standstill

• CEMF decreases with speed

• CEMF remains constant regardless of speed

What are the factors that affect motor speed?

• Applied voltage

• Load torque

• Field flux

• wire size

• housing color

What happens to the speed of a motor under load compared to no load situation

• Speed decreases

• Speed doesn't change

• Speed increase

• Speed oscillate

What happens to the current if the load increase?

• Current increases

• Current decreases

• Current doesn't change

• Current is 0

How does reduced flux density affect motor acceleration?

• It slow down acceleration
  

• Stops the motor

• No effect

• It increases acceleration

which of the following methods is used to reduce current at start-up of large motors?

• Star-Delta

• Auto-Transformer

• Soft-Start

• DOL

• DC power supply

An induction motor has nominal current of 1.5A, what is the starting current?

• 7.5-12A

• 15-20A

• 25-30A

• 3-5A

What is the starting torque in case of star-delta starting

• 1/3 of full load torque

• 1/2 of full load torque

• full load torque

• 0 torque

Which type of motor is best for accurate and constant speed industrial applications?

• DC motor

• Synchronous motor

• Universal motor

• Stepper motor