Electrical Machines DC generator will not build up voltage if field resistance is more than critical resistance. any one of above. due to wrong direction of rotation. if it has lost residual magnetism. if field resistance is more than critical resistance. any one of above. due to wrong direction of rotation. if it has lost residual magnetism. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC generator in case the brushes are moved so as to bring them in magnetic neutral axis, then, there will be none of above. demagnetisation. cross-magnetisation. cross-magnetization as well as demagnetization. none of above. demagnetisation. cross-magnetisation. cross-magnetization as well as demagnetization. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC series motor is running with a divertor connected across its field winding. If the divertor resistance is reduced then the speed of the motor will remain unaltered. increase. become execessively high. decrease. remain unaltered. increase. become execessively high. decrease. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For satisfactory parallel operation of two transformers which of the following conditions is most essential, percentage impedance of all transformers must be same. polarities of all transformers must be same. MVA rating of all transformer inversely proportional to impedance. voltage ratio of all transformers must be same. percentage impedance of all transformers must be same. polarities of all transformers must be same. MVA rating of all transformer inversely proportional to impedance. voltage ratio of all transformers must be same. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Under which of the following conditions is a dc motor provided with compensating winding used ? 1. Wide range of speed control above normal 2. Wide range of steady load variation with no speed control 3.Wide range of rapid variation in load Select the correct answer using the codes given below : Codes : 1 and 2 2 and 3 1 and 3 1, 2 and 3 1 and 2 2 and 3 1 and 3 1, 2 and 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The air gap between stator and the rotor of the 3 - φ induction motor is kept air gap does not matter. depends on the material of stator and the rotor. as small as possible. as wide as possible. air gap does not matter. depends on the material of stator and the rotor. as small as possible. as wide as possible. ANSWER DOWNLOAD EXAMIANS APP
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