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 What is the effect of armature reaction ? None of the options. Both option B and C. Armature flux distorts the main field flux. Armature flux weakens the main field flux. None of the options. Both option B and C. Armature flux distorts the main field flux. Armature flux weakens the main field flux. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines No load test of 3-phase induction motor gives which of the following? variable loss None of these both A and B constant loss variable loss None of these both A and B constant loss ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC cumulatively compounded motor delivers rated load torque at rated speed. If the series field is short-circuited, then the armature current and speed will both decrease decrease and increase respectively increase and decrease respectively both increase both decrease decrease and increase respectively increase and decrease respectively both increase ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The application that need frequent starting and stopping is blowers. lifts and hoists. jaw crushers. paper mills. blowers. lifts and hoists. jaw crushers. paper mills. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The rotor slots are slightly skewed in squirrel cage induction motor to increase the strength of rotor bars. reduce the magnetic hum and locking tendency of rotor. decrease the amount of copper to be used. provide ease of fabrication. increase the strength of rotor bars. reduce the magnetic hum and locking tendency of rotor. decrease the amount of copper to be used. provide ease of fabrication. ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS