Electrical Machines A dc shunt generator, when commissioned after a major repair of the field system, failed to build Up voltage. It was because field system lost residual magnetism field resistance was higher than critical resistance there was a break in the armature circuit field winding was wrongly connected field system lost residual magnetism field resistance was higher than critical resistance there was a break in the armature circuit field winding was wrongly connected ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Field weakening control method is used for the _________ ? below rated speed above rated speed None of these both A and B below rated speed above rated speed None of these both A and B ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a 3 - Φ IM with line frequency f1 and winding factor kw1 and kw2 for stator and rotor respectively the ratio of per phase stator winding emf E1 to per phase rotor winding emf E2 at standstill is given by E1 / E2 = f1kw1 / f2kw2. E1 / E2 = N1kw1 / N2kw2. E1 / E2 = N1 / N2. E1 / E2 = 1. E1 / E2 = f1kw1 / f2kw2. E1 / E2 = N1kw1 / N2kw2. E1 / E2 = N1 / N2. E1 / E2 = 1. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Series generators are used in which of the following applications? All of these Arc welding. Air crafts. Used as boosters in dc distribution or transmission. All of these Arc welding. Air crafts. Used as boosters in dc distribution or transmission. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The oscillation in a synchronous motor can be damped out by oscillation cannot be damped. maintaining constant excitation. running the motor on leading power factors. providing damper bars in the rotor pole faces. oscillation cannot be damped. maintaining constant excitation. running the motor on leading power factors. providing damper bars in the rotor pole faces. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The stator frame in an induction motor is used to ventilate the armature. provide return path for the flux. hold armature stamping in position. protect the whole machine. ventilate the armature. provide return path for the flux. hold armature stamping in position. protect the whole machine. ANSWER DOWNLOAD EXAMIANS APP
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