In a synchronous motor, damper windings are provided on? Mark as favorite Copy Link stator frame rotor shaft pole faces none of the above Check Answer
In a synchronous motor, the armature current has large values for? Mark as favorite Copy Link high excitation only low excitation only both high and low excitation none of the above Check Answer
Which of the following losses is not dissipated by the stator core surface in a synchronous motor? Mark as favorite Copy Link Eddy current losses in the conductors Iron losses in the stator Copper losses in the slot portion of the conductors Windage losses Check Answer
In a synchronous motor, the break down torque is? Mark as favorite Copy Link directly proportional to the applied voltage directly proportional to the square of the applied voltage inversely proportional to applied voltage none of the above Check Answer
At no-load, the armature current in a synchronous motor? Mark as favorite Copy Link is zero lags the applied voltage by 90º leads the applied voltage by 90º is in phase with the applied voltage Check Answer
In a synchronous motor running with fixed excitation, when the load is increased three times, its torque angle becomes approximately? Mark as favorite Copy Link one-third twice thrice six times Check Answer
A synchronous motor running with normal excitation adjusts to load increases essentially by increase in? Mark as favorite Copy Link back e.m.f. armature current power factor torque angle Check Answer
The maximum power developed in a synchronous motor occurs at a coupling angle of? Mark as favorite Copy Link 30º 60º 90º 180º Check Answer
When the field of a synchronous motor is under-excited, the power factor will be? Mark as favorite Copy Link leading lagging unity zero Check Answer
Armature of a synchronous machine is kept fixed because? Mark as favorite Copy Link of reducing number of slip rings on the rotor armature is associated with large power as compared to the field circuits of difficulty of providing high voltage insulation on rotor all of the above reasons Check Answer