Electrical Machines Commutators in DC machines have a role of which converts AC to DC. high voltage DC to low voltage DC. none of these. Both AC to DC and DC to AC. AC to DC. high voltage DC to low voltage DC. none of these. Both AC to DC and DC to AC. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In induction motors, there is large decrease in maximum power factor when the dispersion coefficient is ________________. increased. remains same. kept constant to certain value. decreased. increased. remains same. kept constant to certain value. decreased. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Flux density under trailing pole tips in case of generator will either increase or decrease None of these increase decrease either increase or decrease None of these increase decrease ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The frequency of voltage generated by an alternator having 8 poles and rotating at 250 rpm is 50 Hz. 25 Hz. 16.67 Hz. 60 Hz. 50 Hz. 25 Hz. 16.67 Hz. 60 Hz. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 220 ,V 15 , kW 100 rpm shunt motor with armature resistance of 0.25 , W has a rated line current of 68 A and a rated field current of 2.2 A. The change in field flux required to obtain a speed of 1600 rpm while drawing a line current of 52.8 A and a field current of 1.8 A is 36.36% increase 36.36% decrease 36.36% increase 18.18% increase 36.36% increase 36.36% decrease 36.36% increase 18.18% increase ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC generator if field winding attains the critical resistance field winding will burn. machine will generate maximum voltage. the voltage generated will be zero. machine will generate maximum power. field winding will burn. machine will generate maximum voltage. the voltage generated will be zero. machine will generate maximum power. ANSWER DOWNLOAD EXAMIANS APP
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