Electrical Machines Variation in speed by ward-Leonard control of DC motors occurs due to variation in Armature current. Armature voltage. Field excitaion. Supply voltage. Armature current. Armature voltage. Field excitaion. Supply voltage. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A series motor is efficiently suitable for high starting torque operation. none of these. low starting torque operation. constant speed operation. high starting torque operation. none of these. low starting torque operation. constant speed operation. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which motor cannot be started on no load? series motors shunt motors cumulative compound motors both B and C series motors shunt motors cumulative compound motors both B and C ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines At what power factor, the voltage regulation of a transformer can be zero ? Lagging power factor. Leading power factor. Unity power factor. Zero power factor. Lagging power factor. Leading power factor. Unity power factor. Zero power factor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The polarity of a DC generator can be reversed by increasing field current. reversing field electric current as well as direction of rotation. any of above. reversing the field current. increasing field current. reversing field electric current as well as direction of rotation. any of above. reversing the field current. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A transformer core is made up of a silicon steel laminations which has maximum flux density 1 Tesla. If it was cold rolled grain oriented its flux density increases to 1.6 Tesla. What is the saving in core size or area due to cold rolled grain oriented process? 60% 68% 38% 40% 60% 68% 38% 40% ANSWER DOWNLOAD EXAMIANS APP
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