Electrical Machines The frequency of voltage generated by an alternator having 8 poles and rotating at 250 rpm is 25 Hz. 60 Hz. 50 Hz. 16.67 Hz. 25 Hz. 60 Hz. 50 Hz. 16.67 Hz. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Addition of 0.3 % to 4.5 % silicon to iron increases the hysteresis loss. increases the electrical resistivity of iron. None of these reduces the saturation magnetization. increases the hysteresis loss. increases the electrical resistivity of iron. None of these reduces the saturation magnetization. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Field weakening control method is used for the _________ ? below rated speed above rated speed None of these both A and B below rated speed above rated speed None of these both A and B ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC generators, the cause of rapid brush wear may be severe sparking. rough commutator surface. any of above. imperfect contact. severe sparking. rough commutator surface. any of above. imperfect contact. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 6 pole lap connected DC generator with 480 conductors has armature resistance of 0.06 Ω. If the conductors are reconnected to from a wave winding other things remaining unchanged, the value of armature resistance will be 0.54 Ω. 0.01 Ω. 0.06 Ω. 0.54 Ω. 0.54 Ω. 0.01 Ω. 0.06 Ω. 0.54 Ω. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a dc machine, 1. physically, the brush axis is along the direct axis 2. physically, the brush axis is along the interpolar axis 3. schematically, the brush axis is along the direct axis 4. schematically, the brush axis is along the quadrature axis 5. armaturemmf is directed along the brush axis From these, the correct statements are 2, 4, 5 1 , 3, 5 2, 3, 5 1, 4,5 2, 4, 5 1 , 3, 5 2, 3, 5 1, 4,5 ANSWER DOWNLOAD EXAMIANS APP