Synchronous Motors By which of the following methods the constant speed of a synchronous motor can be changed to new fixed value ? By changing the load By changing the applied voltage By interchanging any two phases By changing the supply frequency By changing the load By changing the applied voltage By interchanging any two phases By changing the supply frequency ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors Hunting in a synchronous motor cannot be due to windage friction variable frequency variable load variable supply voltage windage friction variable frequency variable load variable supply voltage ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors The duration of sudden short-circuit test on a synchronous motor is usually about None of these one hour one second one minute None of these one hour one second one minute ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors In a 3-phase synchronous motor, the negative phase sequence exists when the motor is supplied with unbalanced voltage under-loaded None of these over-loaded supplied with unbalanced voltage under-loaded None of these over-loaded 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 increased load has to take more current The rotor strengthens the rotating field causing more motor 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 increased load has to take more current The rotor strengthens the rotating field causing more motor current ANSWER DOWNLOAD EXAMIANS APP