Electrical Machines Minimum allowable resistivity of power transformer insulating oil is generally taken as 4 X 1012 Ω - cm at 27°C and 0.4 X 1012 3 X 1012 Ω - cm at 27°C and 0.3 X 1012 2 X 1012 Ω - cm at 27°C and 0.2 X 1012 1 X 1012 Ω - cm at 27°C and 0.1 X 1012 4 X 1012 Ω - cm at 27°C and 0.4 X 1012 3 X 1012 Ω - cm at 27°C and 0.3 X 1012 2 X 1012 Ω - cm at 27°C and 0.2 X 1012 1 X 1012 Ω - cm at 27°C and 0.1 X 1012 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Armature resistance control method is also called as-----------? constant current control constant voltage control constant power control constant torque control constant current control constant voltage control constant power control constant torque control ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC motors, under trailing pole tips, flux density will_______ ? increase either increase or decrease None of these decrease increase either increase or decrease None of these decrease ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The material used for commutator brushes is mostly copper. cast iron. carbon. mica. copper. cast iron. carbon. mica. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is/are the advantages of parallel operation of alternators? All of these Increase efficiency under light load conditions Increase in reliability continuity supply is maintained All of these Increase efficiency under light load conditions Increase in reliability continuity supply is maintained ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In induction motor the 7th harmonic torque may make the motor rotate at (1 / 7)th synchronous speed. This is called cogging. harmonics. crawling. resonance. cogging. harmonics. crawling. resonance. ANSWER DOWNLOAD EXAMIANS APP
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