Electrical Machines What is the necessity of copper brushes in a dc motors? To convert alternating supply current to direct current. To increase the flux cutting by the rotor. To absorb the mechanical shocks produced during running condition. None of these. To convert alternating supply current to direct current. To increase the flux cutting by the rotor. To absorb the mechanical shocks produced during running condition. None of these. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following voltage regulator is preferred for providing large values of load current? Zener diode shunt regulator. Transistor shunt regulator. Transistor series regulator. None of these Zener diode shunt regulator. Transistor shunt regulator. Transistor series regulator. None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 230 V dc series generator is driven at its rated speed. The no-load voltage across its armature terminals would be 230 V somewhat more than 230 V 6 V somewhat less than 230 V 230 V somewhat more than 230 V 6 V somewhat less than 230 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC generator sparking between brushes and commutator surface may be due to any of the above. over commutation. under commutation. too rapid reversal of current. any of the above. over commutation. under commutation. too rapid reversal of current. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3 stack stepper motor has 12 teeth on stator as well as on rotor. Determine the step size when each stack excited? 10°. 24°. 45°. 30°. 10°. 24°. 45°. 30°. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature core of the rotor bars of dc motors are laminated to reduce mechanical losses. to reduce eddy current loss. to provide better flux linkage. to reduce hysteresis loss. to reduce mechanical losses. to reduce eddy current loss. to provide better flux linkage. to reduce hysteresis loss. ANSWER DOWNLOAD EXAMIANS APP
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