In a synchronous motor, the maximum power developed depends on all of the following except:
(A) rotor excitation
(B) maximum value of coupling angle
(C) direction of rotation
(D) supply voltage
The effect of increasing the load on a synchronous motor running with normal excitation is to___________?
(A) decrease both armature current and power factor
(B) decrease armature current but increase power factor
(C) increase armature current but decrease power factor
(D) increase both its armature current and power factor
Hunting in a synchronous motor cannot be due to___________?
(A) windage friction
(B) variable load
(C) variable frequency
(D) variable supply voltage
In a synchronous motor, the magnitude of stator back e.m.f. & depends on_______________?
(A) d.c. excitation only
(B) speed of the motor
(C) load on the motor
(D) both the speed and rotor flux
The back e.m.f. of a synchronous motor depends on______________?
(A) speed
(B) load
(C) load angle
(D) all of the above
A synchronous motor can be made self starting by providing?
(A) damper winding on rotor poles
(B) damper winding on stator
(C) damper winding on stator as well as rotor poles
(D) none of the above
The shaft of synchronous motor is made of____________?
(A) mild steel
(B) chrome steel
(C) alnico
(D) stainless steel
The operating speed of a synchronous motor can be changed to new fixed value by___________?
(A) changing the load
(B) changing the supply voltage
(C) changing frequency
(D) using brakes
The maximum power developed in a synchronous motor occurs at a coupling angle of____________?
(A) 30°
(B) 60°
(C) 90°
(D) 180°
In which of the following motors the stator and rotor magnetic field rotate at the same speed?
(A) Universal motor
(B) Synchronous motor
(C) Induction motor
(D) Reluctance motor