Electrical Machines The armature mmf in a dc machine is 1. stationary with respect to field poles 2. stationary with respect to armature 3. rotating with respect to field poles 4. rotating with respect to armature From these, the correct answer is 2, 4 1, 3 1, 4 2, 3 2, 4 1, 3 1, 4 2, 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The rotor speed of an induction motor is given by Ns = 120f /p × ( 1 - r). Ns = 120f / p × ( 1 - s ). None of these Nr = 120f / p × (1-s). Ns = 120f /p × ( 1 - r). Ns = 120f / p × ( 1 - s ). None of these Nr = 120f / p × (1-s). ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A transformer has resistance and reactance in per unit as 0.01 and 0.04 respectively. Its voltage regulation for 0.8 power factor lagging and leading will be 4.8% and -3.2% 6% and -4% None of these 3.2% and -1.6% 4.8% and -3.2% 6% and -4% None of these 3.2% and -1.6% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For a 3 - Φ, 4 pole, 50 Hz IM rotating at full load speed of 1440 rpm, calculate speed of rotor field with respect to rotor structure and stator structure respectively? 1440, 1500. 60, 1500. 50, 1500. 60, 1440. 1440, 1500. 60, 1500. 50, 1500. 60, 1440. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Satisfactory commutation of DC machine requires brushes should smoothly run in the holders. All of these brushes should be of proper grade and size. smooth, concentric commutator properly undercut. brushes should smoothly run in the holders. All of these brushes should be of proper grade and size. smooth, concentric commutator properly undercut. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC motor with armature resistance of 0.5 ohms is connected directly to a 230 Volt supply. If the armature is stationary then the current flowing through armature is 460 A. 570 A. 340 A. 250 A. 460 A. 570 A. 340 A. 250 A. ANSWER DOWNLOAD EXAMIANS APP
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