Electrical Machines The flux involved in the emf equation of a transformer has average value. maximum value. rms value. total value. average value. maximum value. rms value. total value. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A dc shunt generator, when driven without any excitation, showed an open circuit voltage of 12 V. When the field winding was excited, the voltage dropped to zero. It happened because there was a break in the armature circuit there was no residual magnetism in the field circuit field winding was wrongly connected field resistance was higher than critical resistance there was a break in the armature circuit there was no residual magnetism in the field circuit field winding was wrongly connected field resistance was higher than critical resistance ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 200 V DC machine supplies 20 A at 200 V as a generator. The armature resistance is 0.2 Ω. If the machine is now operated as a motor at same terminal voltage and current but with the flux increased by 10%, the ratio of motor speed to generator speed is 1.06 0.95 0.96 0.87 1.06 0.95 0.96 0.87 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The rotor power output of 3-phase induction motor is 15 KW. The rotor copper losses at a slip of 4% will be 650 W 600 W 700 W 625 W 650 W 600 W 700 W 625 W ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Synchronising power of a synchronous motor varies directly as Xs2 directly as synchronous reactances Xs inversely as 1/Xs All of these directly as Xs2 directly as synchronous reactances Xs inversely as 1/Xs All of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3 stack stepper motor has 12 teeth on stator as well as on rotor. Determine the step size when each stack excited? 24°. 45°. 30°. 10°. 24°. 45°. 30°. 10°. ANSWER DOWNLOAD EXAMIANS APP