Electrical Machines A commutator with a diameter of 50 cm rotating at 1000 rpm. For a brush width of 1.5 cm, find the time of commutation in ms. 0.512. 0.443. 0.573. 0.649. 0.512. 0.443. 0.573. 0.649. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC machines, the interpoles are provided to counteract demagnetizing effect of armature mmf in commutating zone. to counteract the reactance voltage and the cross-magnetizi to make commutation spark less. both (B) and (C). to counteract demagnetizing effect of armature mmf in commutating zone. to counteract the reactance voltage and the cross-magnetizi to make commutation spark less. both (B) and (C). ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The demagnetising component of armature reaction in a DC generator results in sparking trouble. increases armature speed. reduces inter poles flux density. reduces generator emf. results in sparking trouble. increases armature speed. reduces inter poles flux density. reduces generator emf. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A series generator is connected in series to a feeder having 0.5Ω resistance to boost the voltage. The induced voltage is given by Eg = 0.6Ia, Ra = 0.2Ω and Rs = 0.3Ω. Find the voltage boosted by the generator, when delivering 400 Amp? 60 V. 40 V. 30 V. 90 V. 60 V. 40 V. 30 V. 90 V. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following generators are used in arc welding? differential compound generators series generators cumulative compound generators shunt generators differential compound generators series generators cumulative compound generators shunt generators ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For a given torque, reducing divertor resistance of a DC series motor Increase in speed but armature currnet remains the same. Decrease in speed demanding less armature current. Decrease in speed but armature current remains the same. Increase in speed demanding more armature current. Increase in speed but armature currnet remains the same. Decrease in speed demanding less armature current. Decrease in speed but armature current remains the same. Increase in speed demanding more armature current. ANSWER DOWNLOAD EXAMIANS APP
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