Synchronous Motors The ratio of starting torque to running torque in a synchronous motor is Infinity Zero One Two Infinity Zero One Two ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors If one phase of a 3 phase synchronous motor is short circuited, motor Will overheat in spots Will not come upto speed Will fail to pull into step Will refused ro start Will overheat in spots Will not come upto speed Will fail to pull into step Will refused ro start ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors In a synchronous motor, the maximum power developed depends on all of the following except maximum value of coupling angle direction of rotation supply voltage rotor excitation maximum value of coupling angle direction of rotation supply voltage rotor excitation ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors The angle between the rotor poles and stator poles, in a synchronous motor, is known as Synchronising angle Power factor angle Torque angle Angle of retardation Synchronising angle Power factor angle Torque angle Angle of retardation ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors A synchronous motor connected to infinite bus-bars has at constant full load, 100% excitation and unity power factor. On changing the excitation only, the armature current will have leading power factor with under-excitation leading power factor with over-excitation lagging power factor with over-excitation no change of power factor leading power factor with under-excitation leading power factor with over-excitation lagging power factor with over-excitation no change of power factor 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