Electrical Machines Eg (generated emf) and Eb (back emf) both are same. changes. none of above. different. same. changes. none of above. different. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines An ideal synchronous motor has no starting torque because rotor winding is highly reactive. rotor is made up of salient poles. relative velocity between stator and rotor mmf’s is not zero. relative velocity between the stator and rotor mmf’s is zero. rotor winding is highly reactive. rotor is made up of salient poles. relative velocity between stator and rotor mmf’s is not zero. relative velocity between the stator and rotor mmf’s is zero. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Fifth harmonic component of the induced voltage in three phase AC generator can be eliminated by using a winding pitch of 5 / 6. 2 / 3. 6 / 7. 4 / 5. 5 / 6. 2 / 3. 6 / 7. 4 / 5. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 250 volt dc series motor having an armature resistance of 0.2 Ω takes a load current of 60 A. What will be the torque produced at the shaft of the motor? Consider brush drop of 1V. can not be determined. 234.76 N-m. 133.22 N-m 266.20 N-m. can not be determined. 234.76 N-m. 133.22 N-m 266.20 N-m. 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, 2, 5 1, 2, 6 1, 4, 6 1, 3, 5 1, 2, 5 1, 2, 6 1, 4, 6 1, 3, 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 8 pole, 50 Hz single phase induction motor is running at 690 rpm. Its slip with respect to forward field is -1.92 0.08 1.92 -0.08 -1.92 0.08 1.92 -0.08 ANSWER DOWNLOAD EXAMIANS APP
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