Under which of the following conditions hunting of synchronous motor is likely to occur?
A. Periodic variation of load
B. Over-excitation
C. Over-loading for long periods
D. Small and constant load
A. Periodic variation of load
B. Over-excitation
C. Over-loading for long periods
D. Small and constant load
A. power factor as well as armature current will decrease
B. power factor as well as armature current will increase
C. power factor will increase but armature current will decrease
D. power factor will decrease and armature current will increase
A. the increased load has to take more current
B. the rotor by shifting its phase backward causes motor to take more current
C. the back e.m.f. decreases causing an increase in motor current
D. the rotor strengthens the rotating field casuing more motor current
A. zero
B. 45°
C. 90°
D. 120°
A. pony motor
B. D.C. compound motor
C. providing damper winding
D. any of the above
A. small induction motor
B. D.C. series motor
C. D.C. shunt motor
D. double winding A.C./D.C. motor
A. the motor stops
B. it runs as a reluctance motor at the same speed
C. it runs as a reluctance motor at a lower speed
D. none of the above
A. under-loaded
B. over-loaded
C. under-excited
D. over-excited
A. alternator type machines
B. induction type machines
C. salient pole type machines
D. smooth cylindrical type machines
A. gear train arrangement
B. transmission of mechanical power by shaft
C. distribution transformer
D. turbine
E. none of the above