Electrical Machines Iron losses in a DC machine are independent of variation in speed and voltage. load. voltage. speed. speed and voltage. load. voltage. speed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Series generators are used in which of the following applications? Air crafts. Used as boosters in dc distribution or transmission. Arc welding. All of these Air crafts. Used as boosters in dc distribution or transmission. Arc welding. All of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements regarding the speed control of dc motors : 1. ward-leonard method is suitable forconstant-torque drives 2. Ward-leonard method is suitable for constant-power drives 3. field-control method facilitates speed control below base speed 4. Armature-resistance control method is more efficient than ward-leanard method 5. Field-control method is suitable for constant-torque drives 6. Armature-resistance control method is suitable for constant-torque drives From these, the correct answer is 1, 4, 6 1, 3, 5 1, 2, 6 1, 2, 5 1, 4, 6 1, 3, 5 1, 2, 6 1, 2, 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines To avoid formation of grooves in the commutator the brushes of same polarity should track each other. the brushes of opposite polarity should track each other. None of these brush position has no effect on the commutator grooving. the brushes of same polarity should track each other. the brushes of opposite polarity should track each other. None of these brush position has no effect on the commutator grooving. 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 cross-magnetisation. demagnetisation. none of above. cross-magnetization as well as demagnetization. cross-magnetisation. demagnetisation. none of above. cross-magnetization as well as demagnetization. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The speed regulation of a DC motor is given as (NfL − NnL)/NnL. NnL − NfL. NnL/NfL. (NnL − NfL)/NfL. (NfL − NnL)/NnL. NnL − NfL. NnL/NfL. (NnL − NfL)/NfL. ANSWER DOWNLOAD EXAMIANS APP
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