Electrical Machines Mechanical energy is supplied to DC generator at the rate of 4200 J / s. The generator delivers 32.2 Amp at 120 V. What is the percentage efficiency of the generator? 210 V. 212 V. 205 V. 201.02 V. 210 V. 212 V. 205 V. 201.02 V. 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 0.96 0.87 0.95 1.06 0.96 0.87 0.95 1.06 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 flux waveform is improved with reduction in harmonics the interpoles produce additional flux to augment the developed torque 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 flux waveform is improved with reduction in harmonics the interpoles produce additional flux to augment the developed torque ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is/are the necessary conditions for parallel operation of alternators? Terminal voltage is same Frequency should be same Speed of alternators should be same Both 1and 2 Terminal voltage is same Frequency should be same Speed of alternators should be same Both 1and 2 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Eg (generated emf) and Eb (back emf) both are none of above. changes. same. different. none of above. changes. same. different. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Iron loss in a transformer mainly occurs in transformer insulating oil. steel core in transformer. iron made tank of transformer. winding of transformer. transformer insulating oil. steel core in transformer. iron made tank of transformer. winding of transformer. ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS