[amp_mcq option1=”maintaining constant excitation” option2=”running the motor on leading power factors” option3=”providing damper bars in the rotor pole faces” option4=”oscillations cannot be damped” correct=”option3″]
Detailed SolutionThe oscillations in a synchronous motor can be damped out by
[amp_mcq option1=”armature current and field current” option2=”power factor and speed” option3=”field current and speed” option4=”field current and power factor” correct=”option3″]
Detailed SolutionIn a synchronous motor, V-curves represent relation between
[amp_mcq option1=”the armature current is maximum” option2=”the armature current is minimum” option3=”the armature current is zero” option4=”none of the above” correct=”option4″]
Detailed SolutionPower factor of a synchronous motor is unity when
[amp_mcq option1=”locked-rotor torque” option2=”synchronous torque” option3=”pull up torque” option4=”reluctance torque” correct=”option1″]
[amp_mcq option1=”more than the supply voltage” option2=”less than the supply voltage” option3=”equal to the supply voltage” option4=”none of the above” correct=”option2″]
Detailed SolutionThe induced e.m.f. in a synchronous motor working on leading power factor will be
[amp_mcq option1=”high excitation only” option2=”low excitation only” option3=”both (A) and (B)” option4=”none of the above” correct=”option1″]
Detailed SolutionThe armature current of the synchronous motor has higher values for
[amp_mcq option1=”lower stability limit” option2=”high stability limit” option3=”good speed regulation” option4=”good voltage regulation” correct=”option1″]
Detailed SolutionA synchronous machine with low value of short-circuit ratio has
[amp_mcq option1=”slip torque” option2=”pull-out torque” option3=”breaking torque” option4=”synchronising torque” correct=”option2″]
[amp_mcq option1=”3000 r.p.m.” option2=”1500 r.p.m.” option3=”750 r.p.m.” option4=”none of the above” correct=”option3″]