Electrical Machines In a DC generator, if P be the number of poles and N be the rpm of the rotor, then frequency of magnetic reversals will be PN/3000. PN/2. PN/60. PN/120. PN/3000. PN/2. PN/60. PN/120. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC generator sparking between brushes and commutator surface may be due to under commutation. too rapid reversal of current. over commutation. any of the above. under commutation. too rapid reversal of current. over commutation. any of the above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A self-excited shunt generator fails to build up, because 1. the field circuit is open 2. The armature circuit is open 3. the residual magnetism is absent 4. The direction of rotation is wrong From these, the correct answer is 1, 2, 3 and 4 1, 3 3 only 1, 2 and 3 1, 2, 3 and 4 1, 3 3 only 1, 2 and 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Damper winding is used to increase the load current. suppress the hunting. decrease the load current. both 1 and 2. increase the load current. suppress the hunting. decrease the load current. both 1 and 2. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In case of DC shunt motor if load is reduced The speed will remains almost constant. DC Shunt Motor The speed will increase in proportion to reduction in load. The speed will increase abruptly. The speed will remains almost constant. DC Shunt Motor The speed will increase in proportion to reduction in load. The speed will increase abruptly. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In an auto transformer, for what value of turn ratio, power transferred by inductively and conductively are same? 0.5 1 0 any of the above 0.5 1 0 any of the above ANSWER DOWNLOAD EXAMIANS APP
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