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 supply frequency By changing the applied voltage By changing the load By interchanging any two phases By changing the supply frequency By changing the applied voltage By changing the load By interchanging any two phases ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors When the synchronous motor is pulled out of synchronism, the stator current _______ Becomes zero Is increased too much Remains unchanged Is decreased too much Becomes zero Is increased too much Remains unchanged Is decreased too much ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors A synchronous motor will always stop when Supply voltage frequency changes Excitation winding gets disconnected Load in motor varies Supply voltage fluctuates Supply voltage frequency changes Excitation winding gets disconnected Load in motor varies Supply voltage fluctuates ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors The induced e.m.f. in a synchronous motor working on leading power factor will be equal to the supply voltage None of these less than the supply voltage more than the supply voltage equal to the supply voltage None of these less than the supply voltage more than the supply voltage ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors If the field circuit of an unloaded salientpole synchronous motor gets suddenly open-circuited, then it runs at a very high speed the motor stops it runs at a slower speed it continues to run at the same speed it runs at a very high speed the motor stops it runs at a slower speed it continues to run at the same speed 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 back e.m.f. decreases causing an increase in motor current The increased load has to take more current The rotor strengthens the rotating field causing more motor current The rotor by shifting its phase backward causes motor to take more current The back e.m.f. decreases causing an increase in motor current The increased load has to take more current The rotor strengthens the rotating field causing more motor current ANSWER DOWNLOAD EXAMIANS APP
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