Electrical Machines The residual magnetism of a self-excited dc generator is lost. To build up its emf again the field winding must be replaced the field winding connection must be reversed field winding must be excited by low voltage dc supply the armature connection must be reversed the field winding must be replaced the field winding connection must be reversed field winding must be excited by low voltage dc supply the armature connection must be reversed ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A transformer has maximum efficiency at 3/4 load. The ratio of iron loss and full load copper loss is 9/16. 4/3. 16/9. 3/4. 9/16. 4/3. 16/9. 3/4. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following machines have highest power factor with respect to magnetizing current? Closed slot type machines. Any of the above. Open slot type machines. Semi closed slot type machine. Closed slot type machines. Any of the above. Open slot type machines. Semi closed slot type machine. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following is done in speed control of DC motor by field flux control? Inserting resistance to armature circuit and field circuit. Any of above. Inserting an additional resistance in the armature circuit. Inserting an additional resistance in the field circuit. Inserting resistance to armature circuit and field circuit. Any of above. Inserting an additional resistance in the armature circuit. Inserting an additional resistance in the field circuit. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The supply voltage to an induction motor is reduced by 10%. By what percentage, approximately, will the maximum torque decrease? 19% 40% 5% 10% 19% 40% 5% 10% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which motor cannot be started on no load? cumulative compound motors series motors both B and C shunt motors cumulative compound motors series motors both B and C shunt motors ANSWER DOWNLOAD EXAMIANS APP
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