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. 0.649. 0.573. 0.443. 0.512. 0.649. 0.573. 0.443. 0.512. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For the speed control of polyphase squirrel cage induction motor, if frequency of operation is decreased with constant supply voltage V, starting torque Tst decreases constant V, Tst increases either of these None of these constant supply voltage V, starting torque Tst decreases constant V, Tst increases either of these None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The polarity of a DC generator can be reversed by any of above. increasing field current. reversing the field current. reversing field electric current as well as direction of rotation. any of above. increasing field current. reversing the field current. reversing field electric current as well as direction of rotation. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines As compared to an induction motor, the air gap in a DC motor is less than 50%. same. between 50% and 90%. more. less than 50%. same. between 50% and 90%. more. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Reactive power generated or delivered significantly depends on load angle. both 1 and 2. excitation. frequency. load angle. both 1 and 2. excitation. frequency. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A single-phase transformer has its maximum efficiency at 60 percent of full load. At full load copper loss will be equal to core loss. more than core loss. zero. less than core loss. equal to core loss. more than core loss. zero. less than core loss. ANSWER DOWNLOAD EXAMIANS APP
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