Electrical Machines The mechanical power is developed by a DC motor is maximum when none of above. back emf is equal to half of applied voltage. back emf is equal to applied voltage. back emf is equal to twice of applied voltage. none of above. back emf is equal to half of applied voltage. back emf is equal to applied voltage. back emf is equal to twice of applied voltage. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC motor with armature resistance of 0.5 ohms is connected directly to a 230 Volt supply. If the armature is stationary then the current flowing through armature is 340 A. 460 A. 570 A. 250 A. 340 A. 460 A. 570 A. 250 A. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In 3 - Φ induction motor some times copper bars are placed deep in the rotor to improve starting torque. improve efficiency. improve power factor. reduce copper loss. improve starting torque. improve efficiency. improve power factor. reduce copper loss. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a 6 pole DC machine, 90 mechanical degrees correspond to which of the following electrical degree? 180. 30. 270. 45. 180. 30. 270. 45. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines To avoid formation of grooves in the commutator the brushes of same polarity should track each other. brush position has no effect on the commutator grooving. the brushes of opposite polarity should track each other. None of these the brushes of same polarity should track each other. brush position has no effect on the commutator grooving. the brushes of opposite polarity should track each other. None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4 pole wave wound dc motor having flux per pole of 9.56 X 10-3 Wb contains 460 armature conductors. Calculate the back emf produced when it is running at a speed of 1500 rpm. 220 volt. 440 volt. 230 volt. 240 volt. 220 volt. 440 volt. 230 volt. 240 volt. ANSWER DOWNLOAD EXAMIANS APP
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