Electrical Machines Which of the following induction motor has maximum speed? 6 pole. 2 pole. 8 pole. 4 pole. 6 pole. 2 pole. 8 pole. 4 pole. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The brushes of a DC machine should be placed on the commutator in the polar axis. armature midway between poles. armature in the polar axis. commutator in the inter polar axis. commutator in the polar axis. armature midway between poles. armature in the polar axis. commutator in the inter polar axis. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The magnetic field which initially induces emf in the armature in a self excited DC generator is because of residual magnetism. permanent magnets. armature reaction. None of these residual magnetism. permanent magnets. armature reaction. None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In shunt dc motor the direction of rotation of the motor will reversed. When only field terminals are changed. only armature terminals are reversed. either field terminals are reversed or armature terminals are reversed. none of above. only field terminals are changed. only armature terminals are reversed. either field terminals are reversed or armature terminals are reversed. none of above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In dc machines, 1. reactance voltage is proportional to armature current 2.reactance voltage is proportional to core length 3.reactance voltage is due to self-flux of the coil undergoing commutation 4. armature-cross flux is neutralized by interpolar flux 5. interpolarmmf is more than armature mmf in the interpolar zone From these, the correct answer is 1, 2, 3, 4 2, 3, 4 1, 3, 5 1, 2, 5 1, 2, 3, 4 2, 3, 4 1, 3, 5 1, 2, 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Maximum allowable tan - delta (tanδ) of dielectric dispassion factor of power transformer insulating oil is generally taken as 3 at 90°C. 2 at 90°C. 1 at 90°C. 0.5 at 90°C. 3 at 90°C. 2 at 90°C. 1 at 90°C. 0.5 at 90°C. ANSWER DOWNLOAD EXAMIANS APP