Electrical Machines When a transformer is loaded, the secondary terminal voltage drops. That means power factor is lagging. unity. zero. leading. lagging. unity. zero. leading. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The rotor speed of an induction motor is given by 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). Ns = 120f /p × ( 1 - r). Ns = 120f / p × ( 1 - s ). ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 240 V, dc shunt motor draws 15 A while supplying the rated load at a speed of 80 rad/s. The armature resistance is 0.5 W and the field winding resistance is 80 W. The net voltage across the armature resistance at the time of plugging will be 474 V 234 V 240 V 6 V 474 V 234 V 240 V 6 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If in a sub – station there is one 132 / 33 kV transformer whose secondary is connected with primary of one 33 / 11 kV transformer, the total transformation ratio of the sub – station will be, 3. 7. 12. 4. 3. 7. 12. 4. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Armature flux is.............with respect to main field flux or main field poles? stationary rotates same direction rotates opposite direction None of these stationary rotates same direction rotates opposite direction None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The introduction of interpoles in between the main poles improves the performance of a dc machine, because a counter-emf is induced in the coil undergoing commutation the inequality of air-gap flux on the top and bottom halves of the armature is removed the interpoles produce additional flux to augment the developed torque the flux waveform is improved with reduction in harmonics a counter-emf is induced in the coil undergoing commutation the inequality of air-gap flux on the top and bottom halves of the armature is removed the interpoles produce additional flux to augment the developed torque the flux waveform is improved with reduction in harmonics ANSWER DOWNLOAD EXAMIANS APP
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