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. 4. 7. 12. 3. 4. 7. 12. 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 = 1. E1 / E2 = N1kw1 / N2kw2. E1 / E2 = f1kw1 / f2kw2. E1 / E2 = N1 / N2. E1 / E2 = 1. E1 / E2 = N1kw1 / N2kw2. E1 / E2 = f1kw1 / f2kw2. E1 / E2 = N1 / N2. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4 pole 50 Hz 1-phase induction motor is running at 1470 rpm. Find the forward and backward slips? 0.04, 1.96 0.04, 0.96 0.02, 1.98 0.02, 0.98 0.04, 1.96 0.04, 0.96 0.02, 1.98 0.02, 0.98 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A transformer core is made up of a silicon steel laminations which has maximum flux density 1 Tesla. If it was cold rolled grain oriented its flux density increases to 1.6 Tesla. What is the saving in core size or area due to cold rolled grain oriented process? 38% 40% 60% 68% 38% 40% 60% 68% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Two transformers operating in parallel will share the load depending on their efficiency per unit impedance ratings leakage reactance efficiency per unit impedance ratings leakage reactance ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC generator, which component plays the vital role to produce the direct current? Armature. Yoke. Commutator. Brush. Armature. Yoke. Commutator. Brush. ANSWER DOWNLOAD EXAMIANS APP
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