Electrical Machines Saving of copper in auto transformer is increased as compared to two winding transformer, when transformation ratio K approaches to two. infinity. unity. zero. two. infinity. unity. zero. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which one of the following statement is correct ? In an induction motor if the air gap is increased then its speed will increase its efficiency will improve its speed will reduce its power factor will reduce its speed will increase its efficiency will improve its speed will reduce its power factor will reduce ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Short circuiting is caused in the armature winding due to any of above. grounding of two or more turns of the same coil. failure of insulation between two commutator bars. failure of insulation between two turns of coil. any of above. grounding of two or more turns of the same coil. failure of insulation between two commutator bars. failure of insulation between two turns of coil. 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 2, 4, 5, 6 1, 2, 5 3, 4, 5 2, 3, 6 2, 4, 5, 6 1, 2, 5 3, 4, 5 2, 3, 6 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A commutator in dc machine provide ----------------- rectification? full wave controlled full wave half wave half wave controlled full wave controlled full wave half wave half wave controlled ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines At what power factor, the voltage regulation of a transformer can be zero ? Zero power factor. Lagging power factor. Unity power factor. Leading power factor. Zero power factor. Lagging power factor. Unity power factor. Leading power factor. ANSWER DOWNLOAD EXAMIANS APP