Synchronous Motors If the field circuit of an unloaded salientpole synchronous motor gets suddenly open-circuited, then it continues to run at the same speed it runs at a very high speed it runs at a slower speed the motor stops it continues to run at the same speed it runs at a very high speed it runs at a slower speed the motor stops ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors When a synchronous motor is pulled out of synchronism, the stator current ________ Become zero Remains unchanged Is increased too much Is decreased too much Become zero Remains unchanged Is increased too much Is decreased too much ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors As the load is applied to a synchronous motor, the motor takes more armature current because 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 The back e.m.f. decreases causing an increase in motor current ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors A synchronous motor will always stop when Excitation winding gets disconnected Supply voltage fluctuates Supply voltage frequency changes Load in motor varies Excitation winding gets disconnected Supply voltage fluctuates Supply voltage frequency changes Load in motor varies ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors The efficiency of a properly designed synchronous motor will usually fall in range 60 to 70% 99 to 99.5% 75 to 80% 85 to 95% 60 to 70% 99 to 99.5% 75 to 80% 85 to 95% ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors A synchronous motor with large air gap has A higher value of stability limit All of the listed here A higher synchronizing power which makes the machine less sensitive to load variations A small value of inherent regulation A higher value of stability limit All of the listed here A higher synchronizing power which makes the machine less sensitive to load variations A small value of inherent regulation ANSWER DOWNLOAD EXAMIANS APP
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