Electrical Machines The material used for commutator brushes is mostly cast iron. carbon. copper. mica. cast iron. carbon. copper. mica. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In large sized DC machines the compensating windings are provided to reduce eddy current losses by providing local short circuits. neutralize voltage induced in coil due to fluctuation of l None of these compensate for the decrease in speed due to increase of load. reduce eddy current losses by providing local short circuits. neutralize voltage induced in coil due to fluctuation of l None of these compensate for the decrease in speed due to increase of load. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The supply voltage to an induction motor is reduced by 10%. By what percentage, approximately, will the maximum torque decrease? 40% 10% 5% 19% 40% 10% 5% 19% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The direction of rotation of a DC motor can be determent by Flemings right hand rule. Amperes law. Flemings left hand rule. Lenzs law. Flemings right hand rule. Amperes law. Flemings left hand rule. Lenzs law. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In dc machines, the space distribution of air-gap flux density wave at no load is co- sinusoidal sinusoidal flat-topped rectangular co- sinusoidal sinusoidal flat-topped rectangular 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