Electrical Machines A dc series motor driving and electric train faces a constant power load. It is running at rated speed and rated voltage. If the speed has to be brought down to 0.25 p.u. the supply voltage has to be approximately brought down to 0.5 p.u 0.25 p.u 0.75 p.u 0.125 p.u 0.5 p.u 0.25 p.u 0.75 p.u 0.125 p.u ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature of a DC motor is laminated to reduce hysteresis loss. copper loss. eddy current loss. friction and windage loss. hysteresis loss. copper loss. eddy current loss. friction and windage loss. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC shunt generator working on load, the brushes are moved forward in the direction of rotation, as a result of this, commutation will improve but terminal voltage will fall. worsen and terminal voltage will fall worsen and terminal voltage will rise. improve and terminal voltage will rise . improve but terminal voltage will fall. worsen and terminal voltage will fall worsen and terminal voltage will rise. improve and terminal voltage will rise . ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is power factor of a 3 - φ induction motor at no load? High. Equal to 1. Low. Same as full load. High. Equal to 1. Low. Same as full load. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Flashing the field of DC generator means increasing flux density by adding extra turns of winding. neutralising residual magnetism. making the magnetic losses forces parallel. creating residual magnetism by a DC source. increasing flux density by adding extra turns of winding. neutralising residual magnetism. making the magnetic losses forces parallel. creating residual magnetism by a DC source. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In travelling cranes for hoisting and lowering which type of motor is preferred? Synchronous motor. AC slip ring motor. Single phase induction motor. DC series motor. Synchronous motor. AC slip ring motor. Single phase induction motor. DC series motor. ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS