Dust and dirt accumulation on motor winding will result in? Mark as favorite Copy Link rise in winding temperature increased core losses shorting of coils eddy current flow Check Answer
Which of the following methods is used to start a synchronous motor? Mark as favorite Copy Link Damper winding Star-delta starter Damper winding in conjunction with star-delta starter Resistance starter in the armature circuit Check Answer
Which of the following resistances can be measured by conducting insulation resistance test on a synchronous motor? Mark as favorite Copy Link Phase to phase winding resistance Stator winding to earthed frame Rotor winding to earthed shaft All of the above Check Answer
The induced e.m.f. in a synchronous motor working on leading power factor will be? Mark as favorite Copy Link more than the supply voltage less than the supply voltage equal to the supply voltage none Check Answer
A synchronous motor can be used as a synchronous capacitor when it is? Mark as favorite Copy Link under-loaded over-loaded under-excited Over-excited Check Answer
While starting a synchronous motor by induction motor action, field winding is usually? Mark as favorite Copy Link connected to D.C. supply short-circuited by low resistance kept open-circuited none of the above Check Answer
The operating speed of a synchronous motor can be changed to new fixed value by? Mark as favorite Copy Link changing the load changing the supply voltage changing frequency using brakes Check Answer
A synchronous motor is running with normal excitation. When the load is increased, the armature current drawn by it increases because? Mark as favorite Copy Link speed of the motor is reduced power factor is decreased Eb (back e.m.f.) becomes less than V (applied voltage) Er (net resultant voltage) in armature is increased Check Answer
The shaft of synchronous motor is made of? Mark as favorite Copy Link mild steel chrome steel alnico stainless steel Check Answer
If one-phase of a 3-phase synchronous motor is short-circuited, motor? Mark as favorite Copy Link will refuse to start will overheat in spots will not come up to speed will fail to pull into step Check Answer