Electrical Machines The teeth in the armature of a DC machines are sometimes skewed. This is done to reduce vibrations. eddy electric current loss. hysteresis loss. copper loss. vibrations. eddy electric current loss. hysteresis loss. copper loss. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When a synchronous motor is running at synchronous speed, the damper winding produces damping torqe. both 1 and 2. eddy current torque. no torque. damping torqe. both 1 and 2. eddy current torque. no torque. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Iron losses in a DC machine are independent of variation in voltage. speed and voltage. load. speed. voltage. speed and voltage. load. speed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following motor has negative speed regulation? Differential compound motor Series motor Shunt motor Cumulative compound motors Differential compound motor Series motor Shunt motor Cumulative compound motors ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following machine is invariably provided with forced ventilation? Fractional horse power slow speed motor. 50 MW generator in a power plant. Hermetically sealed motor of refrigerator. Fractional horse power high speed motor. Fractional horse power slow speed motor. 50 MW generator in a power plant. Hermetically sealed motor of refrigerator. Fractional horse power high speed motor. 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 3 1 and 3 1, 2 and 4 2, 3 and 4 1, 2, and 3 1 and 3 1, 2 and 4 2, 3 and 4 ANSWER DOWNLOAD EXAMIANS APP
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