Electrical Machines The supply voltage to an induction motor is reduced by 10%. By what percentage, approximately, will the maximum torque decrease? 19% 5% 10% 40% 19% 5% 10% 40% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following is not a necessary condition to be satisfied for synchronising an incoming alternator to an already operating alternator? same phase sequence same voltage magnitude same frequency same prime mover speed same phase sequence same voltage magnitude same frequency same prime mover speed 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, 2 and 3 1 and 3 2 alone 1 and 2 1, 2 and 3 1 and 3 2 alone ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the emf generated by a 4 pole Lap connected DC Motor rotating at 1500 rpm having 1000 conductors and useful flux per pole is 0.4 mWb. 30 volts. 40 volts. 20 volts. 10 volts. 30 volts. 40 volts. 20 volts. 10 volts. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In dc machines, 1. reactance voltage is proportional to armature current 2.reactance voltage is proportional to core length 3.reactance voltage is due to self-flux of the coil undergoing commutation 4. armature-cross flux is neutralized by interpolar flux 5. interpolarmmf is more than armature mmf in the interpolar zone From these, the correct answer is 2, 3, 4 1, 2, 5 1, 2, 3, 4 1, 3, 5 2, 3, 4 1, 2, 5 1, 2, 3, 4 1, 3, 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the source voltage of a DC motor is increased, which of the following will decrease? Operating speed. Starting torque. Full load current. Starting torque, operating speed, full load current. Operating speed. Starting torque. Full load current. Starting torque, operating speed, full load current. ANSWER DOWNLOAD EXAMIANS APP
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