Test Your Concept - 01

Test Your Concept :

                                                           Subject : MACHINES

                                                      Topic : Synchronous Machines

Q : A synchronous generator connected to an infinite bus is overexcited. Considering only the  reactive power, from the point of view of the system, the machine acts as

A. a capacitor

B. an inductor

C. a resistor

D. as RL circuit


Solution : An overexcited synchronous generator delivers reactive power to load and operates at lagging power factor.

Q : A 3-phase synchronous machine is synchronized with infinite bus. Now the prime-mover is disconnected from synchronous machine. with this, the synchronous machine would.

A. Work as a synchronous motor at a leading p.f.

B. Work as a synchronous motor at a lagging p.f.

C. Work as a 3-phase induction motor at a lagging p.f.

D. stop


Solution : When prime-mover is removed. Then synchronous alternator will works as a synchronous motor and operate at a leading p.f to operating in magnetizing mode.