Electrical Machines Minimum allowable resistivity of power transformer insulating oil is generally taken as 3 X 1012 Ω - cm at 27°C and 0.3 X 1012 4 X 1012 Ω - cm at 27°C and 0.4 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 3 X 1012 Ω - cm at 27°C and 0.3 X 1012 4 X 1012 Ω - cm at 27°C and 0.4 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 A dc shunt generator, when commissioned after a major repair of the field system, failed to build Up voltage. It was because field system lost residual magnetism field resistance was higher than critical resistance there was a break in the armature circuit field winding was wrongly connected field system lost residual magnetism field resistance was higher than critical resistance there was a break in the armature circuit field winding was wrongly connected ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the number of rotor slots is equal to number of stator slots, then motor refuses to start. Hence it is known as cogging. crawling. air gap. relative speed. cogging. crawling. air gap. relative speed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Autotransformer makes effective saving on copper and copper losses, when its transformation ratio is equal to approx to one. very low greater than one. less than one. approx to one. very low greater than one. less than one. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which type of bearing is provided in small induction motors to support the rotor shaft? Cast iron bearings. None of these Ball bearings. Bush bearings. Cast iron bearings. None of these Ball bearings. Bush bearings. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Capacitor start capacitor run provides none. high staring torque and high power factor. high power factor only. high staring torque only. none. high staring torque and high power factor. high power factor only. high staring torque only. ANSWER DOWNLOAD EXAMIANS APP
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