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. 0.443. 0.512. 0.573. 0.649. 0.443. 0.512. 0.573. 0.649. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a three phase star - delta transformer, what is the angle difference between primary and secondary phase voltages? Star side leads by 30°. Star side lags by -30°. Delta side leads by 30°. Delta side lags by -30°. Star side leads by 30°. Star side lags by -30°. Delta side leads by 30°. Delta side lags by -30°. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A short-shunt cumulatively-compounded dc generator builds up a voltage of 220 V at no load at rated speed. If it is operated as a differentially compounded generator, other things remaining the same, it would build up somewhat less than 220 V 220 V 6 V more than 220 V somewhat less than 220 V 220 V 6 V more than 220 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In speed control of DC shunt motor by varying field flux, what may be the value of field regulator? 10 ohm 0.2 ohm 2 ohm. 100 ohm 10 ohm 0.2 ohm 2 ohm. 100 ohm ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the temperature of armature resistance is increased, the speed of a series motor would increase. None of above. not change. decrease. increase. None of above. not change. decrease. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following motor has the highest power factor at full load? Capacitor run Resistance split phase Capacitor start Shaded pole Capacitor run Resistance split phase Capacitor start Shaded pole ANSWER DOWNLOAD EXAMIANS APP