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 interchanging any two phases By changing the applied voltage By changing the supply frequency By changing the load By interchanging any two phases By changing the applied voltage By changing the supply frequency ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors Hunting in a synchronous motor cannot be due to variable frequency variable load windage friction variable supply voltage variable frequency variable load windage friction variable supply voltage ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors The duration of sudden short-circuit test on a synchronous motor is usually about one second None of these one minute one hour one second None of these one minute one hour ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors In a 3-phase synchronous motor, the negative phase sequence exists when the motor is over-loaded supplied with unbalanced voltage None of these under-loaded over-loaded supplied with unbalanced voltage None of these under-loaded ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors As the load is applied to a synchronous motor, the motor takes more armature current because 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 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 ANSWER DOWNLOAD EXAMIANS APP
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