Electrical Machines The residual magnetism of a self-excited dc generator is lost. To build up its emf again 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 the field winding connection must be reversed the field winding must be replaced the armature connection must be reversed ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The air gap between the yoke and armature is dc machine is kept very small All of these to avoid locking of the armature. to avoid over heating. to achieve a stronger magnetic field. All of these to avoid locking of the armature. to avoid over heating. to achieve a stronger magnetic field. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC motor with armature resistance of 0.5 ohms is connected directly to a 230 Volt supply. If the armature is stationary then the current flowing through armature is 340 A. 460 A. 570 A. 250 A. 340 A. 460 A. 570 A. 250 A. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines An alternator is feeding an infinite busbar. Its prime mover is suddenly shutdown. The alternator will start working as induction motor. continue to work as synchronous motor with same direction of rotation. continue to work as alternator but the direction of rotation will reverse. come to stand still. start working as induction motor. continue to work as synchronous motor with same direction of rotation. continue to work as alternator but the direction of rotation will reverse. come to stand still. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a 2 pole lap winding dc machine , the resistance of one conductor is 2Ω and total number of conductors is 100. Find the total resistance 10Ω 100Ω 200Ω 50Ω 10Ω 100Ω 200Ω 50Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In induction motor when the length of the air gap is increased, the magnetizing current of the motor increases while the short circuit current __________________. decreased. increased. kept constant to certain value. remains unchanged. decreased. increased. kept constant to certain value. remains unchanged. ANSWER DOWNLOAD EXAMIANS APP
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