Electrical Machines A dc shunt generator, when commissioned after a major repair of the field system, failed to build Up voltage. It was because 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 field system lost residual magnetism field resistance was higher than critical resistance ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 500 V, 120 KW, 50 Hz, star connected synchronous motor operating at 0.8 power factor leading has full load efficiency of 91%. The armature resistance is equal to 0.08Ω. The magnitude of armature current is nearly equal to 173 A. 240 A. 190 A. 127 A. 173 A. 240 A. 190 A. 127 A. 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? 60% 38% 40% 68% 60% 38% 40% 68% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For the above problem, find the induced voltage of an alternator of it is to deliver a load of 100 A at power factor of 0.8 lagging with terminal voltage of 200 V. 225 V. 230 V. 222 V. 220 V. 225 V. 230 V. 222 V. 220 V. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A synchronous machine has P number of poles, find the relation between electrical angular momentum (ωe) and mechanical angular momentum (ωm)? ωe = P/2*ωm ωe = 2/P*ωm ωe = P*ωm ωe = ωm ωe = P/2*ωm ωe = 2/P*ωm ωe = P*ωm ωe = ωm ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Under which of the following conditions hunting of synchronous motor is likely to occur ? Over-loading for long period. Periodic variation of load. Small and constant load. Over-excitation. Over-loading for long period. Periodic variation of load. Small and constant load. Over-excitation. ANSWER DOWNLOAD EXAMIANS APP
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