Electrical Machines In DC generators, the cause of rapid brush wear may be rough commutator surface. imperfect contact. any of above. severe sparking. rough commutator surface. imperfect contact. any of above. severe sparking. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A compound motor has only shunt field winding. both shunt and series field winding. tertiary winding. only series field winding. only shunt field winding. both shunt and series field winding. tertiary winding. only series field winding. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In the V curve shown in figure below for a synchronous motor, the parameter of Y and X coordinates are, respectively Torque and field current. Armature current and torque. Armature current and field current. Power factor and field current. Torque and field current. Armature current and torque. Armature current and field current. Power factor and field current. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the applied voltage of a certain transformer is increased by 50% and the frequency is reduced by 50%, the maximum flux density will (assuming that the magnetic circuit remains unsaturated) remain the same as the original changes to three times the original value changes to 0.5 times the original value changes to 1.5 times the original value remain the same as the original changes to three times the original value changes to 0.5 times the original value changes to 1.5 times the original value ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For satisfactory parallel operation of two transformers which of the following conditions is most essential, voltage ratio of all transformers must be same. percentage impedance of all transformers must be same. MVA rating of all transformer inversely proportional to impedance. polarities of all transformers must be same. voltage ratio of all transformers must be same. percentage impedance of all transformers must be same. MVA rating of all transformer inversely proportional to impedance. polarities of all transformers must be same. 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 an additional resistance in the field circuit. Inserting an additional resistance in the armature circuit. Inserting resistance to armature circuit and field circuit. Any of above. Inserting an additional resistance in the field circuit. Inserting an additional resistance in the armature circuit. Inserting resistance to armature circuit and field circuit. ANSWER DOWNLOAD EXAMIANS APP
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