Electrical Machines If the full load speed of 3-phase, 50Hz induction motor is 950 rpm, what is its half load speed nearly equals to? 950 rpm 1000 rpm 940 rpm 975 rpm 950 rpm 1000 rpm 940 rpm 975 rpm ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In induction motor when the length of the air gap is increased, the magnetizing current of the motor increases while the short circuit current __________________. kept constant to certain value. remains unchanged. increased. decreased. kept constant to certain value. remains unchanged. increased. decreased. 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. greater than one. less than one. very low approx to one. greater than one. less than one. very low ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The efficiency of a transformer is mainly dependent on dielectric losses. stray losses. copper losses. core losses. dielectric losses. stray losses. copper losses. core losses. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For satisfactory parallel operation of two transformers which of the following conditions is most essential, MVA rating of all transformer inversely proportional to impedance. voltage ratio of all transformers must be same. polarities of all transformers must be same. percentage impedance of all transformers must be same. MVA rating of all transformer inversely proportional to impedance. voltage ratio of all transformers must be same. polarities of all transformers must be same. percentage impedance of all transformers must be same. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Lap winding is prefered for which type of machines? high current and high voltage low current and low voltage high current and low voltage low current and high voltage high current and high voltage low current and low voltage high current and low voltage low current and high voltage ANSWER DOWNLOAD EXAMIANS APP