Electrical Machines What happens if fifth multiples of harmonics is given to induction motor? Either short circuit or open circuit occurs. Fail to start. It will rotates in reverse direction. It will rotates in normal operation. Either short circuit or open circuit occurs. Fail to start. It will rotates in reverse direction. It will rotates in normal operation. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following is/are the advantages of carbon brush over the copper brush? In case of any sparking they will be less damaged than copper brushes They are not hard as copper brush All of these They are self lubricating in nature In case of any sparking they will be less damaged than copper brushes They are not hard as copper brush All of these They are self lubricating in nature ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines To achieve spark less commutation brushes of DC generator are rocked ahead so as to bring them just ahead of magnetic neutral axis. in magnetic neutral axis. just behind the magnetic neutral axis. None of these just ahead of magnetic neutral axis. in magnetic neutral axis. just behind the magnetic neutral axis. None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The leakage reactance of a 3-phase alternator is determined by performing zero power factor and slip tests. open circuit and short circuit tests. open circuit and zero power factor tests. short circuit and slip tests. zero power factor and slip tests. open circuit and short circuit tests. open circuit and zero power factor tests. short circuit and slip tests. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a three phase star - delta transformer, what is the angle difference between primary and secondary phase voltages? Star side leads by 30°. Delta side lags by -30°. Star side lags by -30°. Delta side leads by 30°. Star side leads by 30°. Delta side lags by -30°. Star side lags by -30°. Delta side leads by 30°. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Flux density under leading pole tips in case of generator will either increase or decrease increase None of these decrease either increase or decrease increase None of these decrease ANSWER DOWNLOAD EXAMIANS APP