Electrical Machines The armature core of the rotor bars of dc motors are laminated to reduce mechanical losses. to reduce hysteresis loss. to reduce eddy current loss. to provide better flux linkage. to reduce mechanical losses. to reduce hysteresis loss. to reduce eddy current loss. to provide better flux linkage. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If in a sub – station there is one 132 / 33 kV transformer whose secondary is connected with primary of one 33 / 11 kV transformer, the total transformation ratio of the sub – station will be, 7. 12. 4. 3. 7. 12. 4. 3. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC Motor 3 point starter is used to provide protection against Low-Voltage. all of above. provide overload protection. limit the starting current to a safer value. provide protection against Low-Voltage. all of above. provide overload protection. limit the starting current to a safer value. 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 2, 3 and 4 1 and 3 1, 2 and 4 1, 2, and 3 2, 3 and 4 1 and 3 1, 2 and 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The slip of an induction motor normally does not depend on synchronous speed. rotor speed. core loss component. shaft torque. synchronous speed. rotor speed. core loss component. shaft torque. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The stator core of a 3 - Φ induction motor is laminated in order to reduce the both of the above. eddy current loss. weight of the stator. hysteresis loss. both of the above. eddy current loss. weight of the stator. hysteresis loss. ANSWER DOWNLOAD EXAMIANS APP