20EE2E22-EMD EV-SQ1

In a DC machines, the purpose of placing the armature winding on the rotor is to ___________.

• produce magnetic field

• reduce overall size of the machine

• produce the required output voltage

• eliminate the need of commutator bars

The _______ type of motor is preferred for EV applications due to its high efficiency and low maintenance characteristics.

• DC series motor

• induction motor

• permanent magnet synchronous motor

• switched reluctance motor

The primary function of winding on the rotor in slip ring induction motor is to ____________.

• avoid slip losses

• improve cooling of the motor

• reduce maintenance cost

• provide external resistance for starting

Which of the following statement about Permanent Magnet Brushless DC motor is true?

• It does not require a controller for operation

• It uses brushes for commutation

• Feedback from hall sensors is essential for its operation

• It has higher efficiency and better speed control

A Switched Reluctance Motor does not have any winding on its rotor. The prime reason for this design feature is to _________.

• reduce overall cost of the machine

• decrease the electromagnetic losses

• improve mechanical strength of the rotor

• simplify the construction and reduce the inertia

The _________ is the advantage of having variable reluctance rotor in Synchronous Reluctance Motor

• simple speed control

• reduced starting current

• absence of rotor winding

• improved power factor
  
  

In Permanent Magnet Synchronous Motor, the speed is ___________

• independent of rotor position
  
  

• dependent on rotor position

• directly proportional to stator frequency
  
  

• inversely proportional to stator frequency

The speed regulation of DC motor is typically better than that of an induction motor because _______________.

• DC machine has constant speed operation

• induction motor has slip which affects its speed regulation

• DC machine has a mechanical commutation system

• induction motor has a fixed stator winding

The increase the number of rotor poles ____________  on the speed-torque characteristics of Permanent Magnet Synchronous Motor as compared to a motor with fewer poles.

• decrease the torque pulsations

• increase the maximum torque capability

• decrease the field weakening range

• increase the synchronous speed

The ability of Switched Reluctance Motor to provide high efficiency at various speed-torque operating points is due to ________.

• absence of rotor winding

• variable reluctance design

• use of permanent magnets

• high starting torque