Electrical Machines Under which of the following conditions hunting of synchronous motor is likely to occur ? Over-loading for long period. Small and constant load. Over-excitation. Periodic variation of load. Over-loading for long period. Small and constant load. Over-excitation. Periodic variation of load. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Commutator in DC generator is used for increase efficiency collecting of current convert AC armature current in to DC reduce losses increase efficiency collecting of current convert AC armature current in to DC reduce losses ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In induction motors, there is large decrease in maximum power factor when the dispersion coefficient is ________________. remains same. increased. decreased. kept constant to certain value. remains same. increased. decreased. kept constant to certain value. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The power factor of an induction motor operating at no load will have a value around 0.2 lead 0.9 lag unity 0.2 lag 0.2 lead 0.9 lag unity 0.2 lag ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the mechanical power developed by a DC series motor is maximum? Back emf is equal to applied voltage. None of above. Back emf is equal to half the applied voltage. Back emf is equal to zero. Back emf is equal to applied voltage. None of above. Back emf is equal to half the applied voltage. Back emf is equal to zero. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is/are the necessary conditions for voltage build up in self excited generator? All of these Poles should contain residual flux. Field winding resistance should be less than critical resistance. Field winding should be properly connected to armature winding. All of these Poles should contain residual flux. Field winding resistance should be less than critical resistance. Field winding should be properly connected to armature winding. ANSWER DOWNLOAD EXAMIANS APP
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