Synchronous Motor Multiple Choice Questions and Answers

11. Due to which of the following reasons a synchronous motor fails to pull into synchronism after applying D.C. field current

   A.High field current

   B.Low short circuited ratio

   C.High core losses

   D.Low field current

12. The maximum speed variation in a 3-phase synchronous motor is

   A.10 percent

   B.60 percent

   C.4 percent

   D.2 percent

   E.Zero

13. Which of the following resistances can be measured by conducting insulation resistance test on a synchronous motor

   A.Phase to phase winding resistance

   B.Stator winding to earthed frame

   C.Rotor winding to earthed shaft

   D.All of the above

14. If the field circuit of an unloaded salient pole synchronous motor gets suddenly open-circuited, then

   A.It runs at a slower speed

   B.The motor stops

   C.It continues to run at the same speed

   D.It runs at a very high speed

15. The net armature voltage of a synchronous motor is equal to the

   A.Vector sum of E^b and V

   B.Airthmetic sum of E^b and V

   C.Airthmetic difference of E^b and V

   D.Vector difference of E^b and V

< 1 2 3 4 5 6 7 8 Next>