Electrical Machines The residual magnetism of a self-excited dc generator is lost. To build up its emf again the armature connection must be reversed the field winding must be replaced field winding must be excited by low voltage dc supply the field winding connection must be reversed the armature connection must be reversed the field winding must be replaced field winding must be excited by low voltage dc supply the field winding connection must be reversed ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In synchronous generator V curve is drawn between field current on X-axis and armature current on Y-axis. either of these. field current on Y-axis and armature current on X-axis. field current on X-axis and power factor on Y-axis. field current on X-axis and armature current on Y-axis. either of these. field current on Y-axis and armature current on X-axis. field current on X-axis and power factor on Y-axis. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For the speed control of polyphase squirrel cage induction motor, if frequency of operation is decreased with either of these constant supply voltage V, starting torque Tst decreases None of these constant V, Tst increases either of these constant supply voltage V, starting torque Tst decreases None of these constant V, Tst increases ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Iron losses in a DC machine are independent of variation in speed. voltage. speed and voltage. load. speed. voltage. speed and voltage. load. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements : For a level compounded dc generator to run at constant voltage, the series field mmf must effectively compensate 1. armature reaction mmf 2.armature resistance drop 3. brush contact voltage drop Which of these statements is/are correct ? 1 and 2 1 and 3 1, 2 and 3 2 alone 1 and 2 1 and 3 1, 2 and 3 2 alone ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Why are capacitors used with large AC induction motor? Improve power level. Improve voltage level. Improve current level. Improve power factor. Improve power level. Improve voltage level. Improve current level. Improve power factor. ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS