Electrical Machines Hunting phenomenon is observed in which motor? DC motor. Synchronous motor. Induction motor. Both A and C. DC motor. Synchronous motor. Induction motor. Both A and C. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In travelling cranes for hoisting and lowering which type of motor is preferred? Single phase induction motor. AC slip ring motor. DC series motor. Synchronous motor. Single phase induction motor. AC slip ring motor. DC series motor. Synchronous motor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC generator sparking between brushes and commutator surface may be due to over commutation. under commutation. any of the above. too rapid reversal of current. over commutation. under commutation. any of the above. too rapid reversal of current. 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, 2, 6 1, 2, 5 1, 3, 5 1, 4, 6 1, 2, 6 1, 2, 5 1, 3, 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Voltage across the open circuited field termninals of a synchorous machine under slip test is AC of supply frequency. DC of slip frequency. A modulated supply frequency AC voltage with slip frequency envelop. DC. AC of supply frequency. DC of slip frequency. A modulated supply frequency AC voltage with slip frequency envelop. DC. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature core of the rotor bars of dc motors are laminated to reduce mechanical losses. to reduce eddy current loss. to reduce hysteresis loss. to provide better flux linkage. to reduce mechanical losses. to reduce eddy current loss. to reduce hysteresis loss. to provide better flux linkage. ANSWER DOWNLOAD EXAMIANS APP
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