Electrical Machines With the increase in speed of a DC motor both back emf as well as line current fall. both back emf as well as line current increase. back emf increases but line current falls. back emf falls and line current increases. both back emf as well as line current fall. both back emf as well as line current increase. back emf increases but line current falls. back emf falls and line current increases. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The direction of rotation of a 3 - Φ induction motor can be reversed by transposing any two leads from slip rings. transposing any two leads from supply. transposing all the three leads from the supply. disconnecting any one phase. transposing any two leads from slip rings. transposing any two leads from supply. transposing all the three leads from the supply. disconnecting any one phase. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The air gap between the yoke and armature is dc machine is kept very small to avoid over heating. to avoid locking of the armature. to achieve a stronger magnetic field. All of these to avoid over heating. to avoid locking of the armature. to achieve a stronger magnetic field. All of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a synchronous motor when the rotor speed exceeds the synchronous speed during hunting negative sequence currents are generated. the damper bars develop induction motor torque. the damper bars develop induction generator torque. the damper bars develop synchronous motor torque. negative sequence currents are generated. the damper bars develop induction motor torque. the damper bars develop induction generator torque. the damper bars develop synchronous motor torque. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Armature reaction of an unsaturated DC machine is none of above. crossmagnetising. magnetising. demagnetising. none of above. crossmagnetising. magnetising. demagnetising. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In dc machines, the field system has to be provided on stator unlike synchronous machines Where in it could be on any member, because commutator action is not possible otherwise it reduces field structure iron losses it gives more uniform air-gap flux distribution dc machines are comparatively low rating machines. commutator action is not possible otherwise it reduces field structure iron losses it gives more uniform air-gap flux distribution dc machines are comparatively low rating machines. ANSWER DOWNLOAD EXAMIANS APP