Electrical Machines In a loaded DC generator, if the brushes are given a shift from the interpolar axis in the direction of rotation, then the commutation will deteriorate with rise in terminal voltage. improve with rise in terminal voltage. deteriorate with fall of terminal voltage. improve with fall of terminal voltage. deteriorate with rise in terminal voltage. improve with rise in terminal voltage. deteriorate with fall of terminal voltage. improve with fall of terminal voltage. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A large series motor is never started without some mechanical load on it because otherwise it will produce sparking at brushes. open fuse or circuit breaker. draw too much current. develop excessive speed and damage itself. produce sparking at brushes. open fuse or circuit breaker. draw too much current. develop excessive speed and damage itself. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Slip speed is the sum of synchronous and rotor speeds. difference of synchronous speed and actual rotor speed. difference of actual rotor speed and synchronous speed. half of the sum of synchronous and rotor speeds. sum of synchronous and rotor speeds. difference of synchronous speed and actual rotor speed. difference of actual rotor speed and synchronous speed. half of the sum of synchronous and rotor speeds. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A load of 900 lbs is to be raised with a lift car weighting 855 lbs at a speed of 110 feet per minute, the over balance being 40 % and percentage efficiency 45 %. Find the horse power of the motor without counterweight 160. 150. 180. 170. 160. 150. 180. 170. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines An alternator is feeding an infinite busbar. Its prime mover is suddenly shutdown. The alternator will continue to work as alternator but the direction of rotation will reverse. start working as induction motor. continue to work as synchronous motor with same direction of rotation. come to stand still. continue to work as alternator but the direction of rotation will reverse. start working as induction motor. continue to work as synchronous motor with same direction of rotation. come to stand still. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 500 V, 55 kVA single phase alternator has an effective resistance of 0.5 Ω. An excitation current of 10 A produces 200 A armature current on short circuit and an emf of 450 V on per circuit. The synchronous reactance will be 2.74 Ω. 2.781 Ω. 25.564 Ω. 2.241 Ω. 2.74 Ω. 2.781 Ω. 25.564 Ω. 2.241 Ω. ANSWER DOWNLOAD EXAMIANS APP
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