Synchronous Motors Synchronous motors are generally used in application requiring _______ Infrequent starting Sudden application of heavy loads Variable speed Frequent stopping Infrequent starting Sudden application of heavy loads Variable speed Frequent stopping ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors As the load is applied to a synchronous motor, the motor takes more armature current because The back e.m.f. decreases causing an increase in motor current The rotor by shifting its phase backward causes motor to take more current The rotor strengthens the rotating field causing more motor current The increased load has to take more current The back e.m.f. decreases causing an increase in motor current The rotor by shifting its phase backward causes motor to take more current The rotor strengthens the rotating field causing more motor current The increased load has to take more current ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors In case one phase of a three-phase synchronous motor is short-circuited the motor will run at 2/3 of synchronous speed take less than the rated load not start run with excessive vibrations run at 2/3 of synchronous speed take less than the rated load not start run with excessive vibrations ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors The armature current of the synchronous motor has higher values for Higher excitation only None of the listed here Low excitation only Both higher and low excitation Higher excitation only None of the listed here Low excitation only Both higher and low excitation ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors A synchronous motor with large air gap has A higher synchronizing power which makes the machine less sensitive to load variations A higher value of stability limit All of the listed here A small value of inherent regulation A higher synchronizing power which makes the machine less sensitive to load variations A higher value of stability limit All of the listed here A small value of inherent regulation ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors A three phase synchronous motor will have Two slip rings Three slip rings One slip rings No slip rings Two slip rings Three slip rings One slip rings No slip rings ANSWER DOWNLOAD EXAMIANS APP