Electrical Machines The armature core of the rotor bars of dc motors are laminated 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. to reduce mechanical losses. to reduce hysteresis loss. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The direction of generated emf in the armature coil of a DC machine is 1. the same as that of the current in a generator 2. the same as that of the current in a motor 3. opposite to that of the current in a generator 4. opposite to that of the current in a motor From these, the correct answer is 1, 4 1, 3 2, 3 2, 4 1, 4 1, 3 2, 3 2, 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In escalator which motor is used? Universal motor. 1 - φ IM. DC shunt motor. 3 - φ IM. Universal motor. 1 - φ IM. DC shunt motor. 3 - φ IM. 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 Synchronising power of a synchronous motor varies directly as synchronous reactances Xs inversely as 1/Xs directly as Xs2 All of these directly as synchronous reactances Xs inversely as 1/Xs directly as Xs2 All of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Cross magnetization effects which of the following? commutation reduces the terminal voltage reduction in main field flux both 2 and 3 commutation reduces the terminal voltage reduction in main field flux both 2 and 3 ANSWER DOWNLOAD EXAMIANS APP
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