Electrical Machines The speed of rotating magnetic field of 8 pole 50 Hz induction motor is 1500 rpm 750 rpm 3000 rpm 1000 rpm 1500 rpm 750 rpm 3000 rpm 1000 rpm ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Direct-on-line (DOL) starters are not suitable for starting large DC motors, because the starting torque becomes low. the motor may run away. the motor may not start. the starting current will be enormously high. the starting torque becomes low. the motor may run away. the motor may not start. the starting current will be enormously high. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A dc shunt motor has external resistance Ra and Rf in the armature and field circuits respectively. Armature current at starting can be reduced by keeping Ra maximum and Rf maximum Ra maximum and Rf minimum Rf maximum and Ra minimum Ra minimum and Rf minimum Ra maximum and Rf maximum Ra maximum and Rf minimum Rf maximum and Ra minimum Ra minimum and Rf minimum ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The counter (or back) emf in a dc machine is 1. the same as generated emf in a dc motor 2. proportional to field flux and armature speed 3. not the same as generated emf in a dc motor 4.inversely proportional to field flux 5. proportional to number of armature conductors 6. constant from no load to full load From these, the correct answer is 3, 4, 5 1, 2, 5 2, 4, 5, 6 2, 3, 6 3, 4, 5 1, 2, 5 2, 4, 5, 6 2, 3, 6 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In escalator which motor is used? 3 - φ IM. DC shunt motor. 1 - φ IM. Universal motor. 3 - φ IM. DC shunt motor. 1 - φ IM. Universal motor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 2 pole synchronous machine is operating at 3000 rpm. Find the relation between electrical angular momentum (ωe) and mechanical angular momentum (ωm) ? ωe = 4*ωm ωe = 2*ωm ωe = 1/2*ωm ωe = ωm ωe = 4*ωm ωe = 2*ωm ωe = 1/2*ωm ωe = ωm ANSWER DOWNLOAD EXAMIANS APP
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