Electrical Machines The efficiency of a transformer is mainly dependent on copper losses. core losses. stray losses. dielectric losses. copper losses. core losses. stray losses. dielectric losses. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of following winding is connected in series with armature winding of DC machine? Compensating winding. Commutating pole winding. Auxiliary winding. Both Compensating and Commutating pole winding. Compensating winding. Commutating pole winding. Auxiliary winding. Both Compensating and Commutating pole winding. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The residual magnetism of a self-excited dc generator is lost. To build up its emf again field winding must be excited by low voltage dc supply the field winding must be replaced the armature connection must be reversed the field winding connection must be reversed field winding must be excited by low voltage dc supply the field winding must be replaced the armature connection must be reversed the field winding connection must be reversed ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 200 V DC machine supplies 20 A at 200 V as a generator. The armature resistance is 0.2 Ω. If the machine is now operated as a motor at same terminal voltage and current but with the flux increased by 10%, the ratio of motor speed to generator speed is 0.87 0.96 1.06 0.95 0.87 0.96 1.06 0.95 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3 - Φ, 12 pole, 600 V, 50 Hz star connected IM has rotor resistance and stand still resistance of 0.03 Ω and 0.5 Ω respectively. The speed of maximum torque will be 470 rpm. 450 rpm. 540 rpm. 240 rpm. 470 rpm. 450 rpm. 540 rpm. 240 rpm. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In star-delta starting of squirrel cage induction motor compared to DOL starting the starting current and torque are 1/√3, 1/√3 1/3, 1/√3 1/3, 1/3 1/√3, 1/3 1/√3, 1/√3 1/3, 1/√3 1/3, 1/3 1/√3, 1/3 ANSWER DOWNLOAD EXAMIANS APP
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