Electrical Machines Counter emf of a DC motor regulates its armature voltage. exceeds supply voltage helps in energy conversion. aids applied voltage. regulates its armature voltage. exceeds supply voltage helps in energy conversion. aids applied voltage. ANSWER DOWNLOAD EXAMIANS APP
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 0.75 p.u 0.5 p.u 0.25 p.u 0.125 p.u 0.75 p.u 0.5 p.u 0.25 p.u 0.125 p.u ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The use of higher flux density in the transformer design has no relation with the weight of transformer reduces the weigh per KVA None of these increases the weigh per KVA has no relation with the weight of transformer reduces the weigh per KVA None of these increases the weigh per KVA ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines How can the synchronous speed of a 3 - Φ IM be varied? By varying the supply frequency. By varying supply voltage. Both (A) and (B). By varying number of poles. By varying the supply frequency. By varying supply voltage. Both (A) and (B). By varying number of poles. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider a separately excited DC motor. If the field current is increased while the armature terminal voltage is held constant, then speed of the motor will increase. remains same. none of these. Decrease.d increase. remains same. none of these. Decrease.d 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 worsen and terminal voltage will fall improve but terminal voltage will fall. worsen and terminal voltage will rise. improve and terminal voltage will rise . worsen and terminal voltage will fall improve but terminal voltage will fall. worsen and terminal voltage will rise. improve and terminal voltage will rise . ANSWER DOWNLOAD EXAMIANS APP
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