Electrical Machines The residual magnetism of a self-excited dc generator is lost. To build up its emf again the field winding connection must be reversed the field winding must be replaced the armature connection must be reversed field winding must be excited by low voltage dc supply the field winding connection must be reversed the field winding must be replaced the armature connection must be reversed field winding must be excited by low voltage dc supply ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Sparkless commutation can be achieved by employing high resistance carbon brushes. compensating winding. inter poles. any one or more of the above methods. high resistance carbon brushes. compensating winding. inter poles. any one or more of the above methods. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a transformer which of the following losses are zero? Rotational loss All of these Iron loss Copper loss Rotational loss All of these Iron loss Copper loss ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Poles of DC machine are often laminated to reduce armature reaction. reduce pulsation loss. reduce iron weight. dissipate more heat. reduce armature reaction. reduce pulsation loss. reduce iron weight. dissipate more heat. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Synchronising power of a synchronous motor varies directly as Xs2 inversely as 1/Xs All of these directly as synchronous reactances Xs directly as Xs2 inversely as 1/Xs All of these directly as synchronous reactances Xs ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Slip speed is the difference of synchronous speed and actual rotor speed. half of the sum of synchronous and rotor speeds. difference of actual rotor speed and synchronous speed. sum of synchronous and rotor speeds. difference of synchronous speed and actual rotor speed. half of the sum of synchronous and rotor speeds. difference of actual rotor speed and synchronous speed. sum of synchronous and rotor speeds. ANSWER DOWNLOAD EXAMIANS APP
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