Electrical Machines Demagnetization effects which of the following? both B and C reduces the terminal voltage commutation reduction in main field flux both B and C reduces the terminal voltage commutation reduction in main field flux ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Diverters are used only in shunt motors None of these series motors either of these shunt motors None of these series motors either of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines To have sparkless commutation, the armature reaction effect in a DC machine is neutralized by fixing the brush axis inline with the pole axis. increasing field excitation. compensating winding and commutating poles. shifting the brush axis from GNA to MNA. fixing the brush axis inline with the pole axis. increasing field excitation. compensating winding and commutating poles. shifting the brush axis from GNA to MNA. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines φA DC shunt machine generates 250 V on open circuit at 1000 RPM. Armature resistance is 0.5 Ω, field resistance 250 Ω. When running as a motor takes 4 A at 250 V. Calculate the speed when running as a motor taking 40 A at 250 V. Armature reaction weakens the field by 4%. 970 RPM 940 RPM 920 RPM 960 RPM 970 RPM 940 RPM 920 RPM 960 RPM ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which slots are used in the rotor of an induction motor? Open slots. Closed slots. None of above. Semi closed slots. Open slots. Closed slots. None of above. Semi closed slots. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The residual magnetism of a self-excited dc generator is lost. To build up its emf again the armature connection must be reversed the field winding connection must be reversed field winding must be excited by low voltage dc supply the field winding must be replaced the armature connection must be reversed the field winding connection must be reversed field winding must be excited by low voltage dc supply the field winding must be replaced ANSWER DOWNLOAD EXAMIANS APP