Electrical Machines The power factor of an induction motor operating at no load will have a value around 0.2 lead 0.2 lag unity 0.9 lag 0.2 lead 0.2 lag unity 0.9 lag ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The damper windings also called the squirrel cage windings or damper grids consists of short-circuited copper bars embedded in the field pole faces. are provided in a synchronous motor to make it self starting. are provided on the stator for improving power factor. both (A) and (B). consists of short-circuited copper bars embedded in the field pole faces. are provided in a synchronous motor to make it self starting. are provided on the stator for improving power factor. both (A) and (B). ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Number of slip rings in 3-phase synchronous motor will be 3 or 4 1 2 0 3 or 4 1 2 0 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The sparking at the the brushes, in a DC machines is due to armature reaction. high resistance of carbon brushes. presence of commutator. reactance voltage. armature reaction. high resistance of carbon brushes. presence of commutator. reactance voltage. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines To control the speed of an induction motor, the supply frequency is reduced by 10%. For the same magnetizing current to remain constant, the supply voltage must be reduced by 20% increased by 20% increased by 10% reduced by 10% reduced by 20% increased by 20% increased by 10% reduced by 10% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 250 volt dc series motor having an armature resistance of 0.2 Ω takes a load current of 60 A. What will be the torque produced at the shaft of the motor? Consider brush drop of 1V. can not be determined. 234.76 N-m. 133.22 N-m 266.20 N-m. can not be determined. 234.76 N-m. 133.22 N-m 266.20 N-m. ANSWER DOWNLOAD EXAMIANS APP