Electrical Machines A self-excited shunt generator fails to build up, because 1. the field circuit is open 2. The armature circuit is open 3. the residual magnetism is absent 4. The direction of rotation is wrong From these, the correct answer is 1, 3 1, 2, 3 and 4 1, 2 and 3 3 only 1, 3 1, 2, 3 and 4 1, 2 and 3 3 only ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Flashing the field of DC generator means increasing flux density by adding extra turns of winding. creating residual magnetism by a DC source. making the magnetic losses forces parallel. neutralising residual magnetism. increasing flux density by adding extra turns of winding. creating residual magnetism by a DC source. making the magnetic losses forces parallel. neutralising residual magnetism. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a dc generator operating on load with its brushes on the geometrical neutral axis (GNA), the magnetic neutral axis (MNA) is shifted in the direction of rotation. Now, if the brushes are given a lead of 90° (electrical), then the MNA will shift forward by 90° shift forward by more than 90° shift forward by less than 90° coincide with the GNA shift forward by 90° shift forward by more than 90° shift forward by less than 90° coincide with the GNA ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The rotor power output of 3-phase induction motor is 15 KW. The rotor copper losses at a slip of 4% will be 650 W 625 W 700 W 600 W 650 W 625 W 700 W 600 W ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a synchronous motor torque or load angle δ ------------- with increase in load None of these increases decreases remains unaffected None of these increases decreases remains unaffected ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The efficiency of a transformer is mainly dependent on dielectric losses. stray losses. core losses. copper losses. dielectric losses. stray losses. core losses. copper losses. ANSWER DOWNLOAD EXAMIANS APP
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