Synchronous Motors The speed of a synchronous motor can be changed by varying _______ Mechanical load Supply frequency None of the listed here Field excitation Mechanical load Supply frequency None of the listed here Field excitation 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 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 leading power factor with under-excitation ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors A rotary converter can also be run as a Dc series generator Dc compound generator Dc shunt generator Synchronous motor Dc series generator Dc compound generator Dc shunt generator Synchronous motor ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors If one phase of a 3 phase synchronous motor is short circuited, motor Will refused ro start Will not come upto speed Will fail to pull into step Will overheat in spots Will refused ro start Will not come upto speed Will fail to pull into step Will overheat in spots ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors When a synchronous motor is on no load, the torque angle is about ________ 0° electrical 30° electrical 90° electrical 45° electrical 0° electrical 30° electrical 90° electrical 45° electrical ANSWER DOWNLOAD EXAMIANS APP
Synchronous Motors When load on an over-excited or under excited synchronous motor is increased, rate of change of its armature current as compared with that of power factor is less twice equal more less twice equal more ANSWER DOWNLOAD EXAMIANS APP