Electrical Machines The speed regulation of a DC motor is given as NnL/NfL. (NnL − NfL)/NfL. (NfL − NnL)/NnL. NnL − NfL. NnL/NfL. (NnL − NfL)/NfL. (NfL − NnL)/NnL. NnL − NfL. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following is done in speed control of DC motor by field flux control? Any of above. Inserting resistance to armature circuit and field circuit. Inserting an additional resistance in the armature circuit. Inserting an additional resistance in the field circuit. Any of above. Inserting resistance to armature circuit and field circuit. Inserting an additional resistance in the armature circuit. Inserting an additional resistance in the field circuit. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following factors improve commutation in a dc machine ? 1. High contact resistance of brushes 2. High inductance of the coils undergoing commutation 3. Shifting of brushes in the direction of rotation for a generator and in the opposite direction For a motor 4. Narrow width for the commutation bars Select the correct answer using the codes given below : Codes : 1, 2 and 4 1, 2, and 3 2, 3 and 4 1 and 3 1, 2 and 4 1, 2, and 3 2, 3 and 4 1 and 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Armature resistance control method is also called as-----------? constant torque control constant voltage control constant power control constant current control constant torque control constant voltage control constant power control constant current control ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following is/are the advantages of carbon brush over the copper brush? All of these They are self lubricating in nature They are not hard as copper brush In case of any sparking they will be less damaged than copper brushes All of these They are self lubricating in nature They are not hard as copper brush In case of any sparking they will be less damaged than copper brushes ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature of DC machine is made of silicon steel lamination to reduce hysteresis loss only. reduce both eddy current and hysteresis loss. increase the permeability. reduce eddy current loss only. reduce hysteresis loss only. reduce both eddy current and hysteresis loss. increase the permeability. reduce eddy current loss only. ANSWER DOWNLOAD EXAMIANS APP
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