1
GATE EE 2009
MCQ (Single Correct Answer)
+2
-0.6
A field excitation of $$20A$$ in a certain alternator results in a armature current of $$400$$ $$A$$ in short circuit and a terminal voltage of $$2000$$ $$V$$ on open circuit. The magnitude of the internal voltage drop with in the machine at a load current of $$200$$ $$A.$$
A
$$1$$ $$V$$
B
$$10$$ $$V$$
C
$$100$$ $$V$$
D
$$1000$$ $$V$$
2
GATE EE 2008
MCQ (Single Correct Answer)
+2
-0.6
A synchronous motor is connected to an infinite bus at $$1.0$$ $$p.u$$ voltage and draws $$0.6$$ $$pu$$ at unity power factor. Its synchronous reactance is $$1.0$$ $$pu$$ and resistance is negligible.

The excitation voltage and load angle will respectively be

A
$$0.8$$ $$pu$$ and $$36.86$$ degrees lag
B
$$0.8$$ $$pu$$ and $$36.86$$ degrees lead
C
$$1.17$$ $$pu$$ and $$30.96$$ degrees lead
D
$$1.17$$ $$pu$$ and $$30.96$$ degrees lag
3
GATE EE 2008
MCQ (Single Correct Answer)
+2
-0.6
A synchronous motor is connected to an infinite bus at $$1.0p.u$$ voltage and draws $$0.6$$ $$pu$$ at unity power factor. Its synchronous reactance is $$1.0$$ $$pu$$ and resistance is negligible.

Keeping the excitation voltage same, the load on the motor is increased such that the motor current increases by $$20\% $$. The operating power factor will become

A
$$0.995$$ lagging
B
$$0.995$$ leading
C
$$0.791$$ lagging
D
$$0.848$$ leading
4
GATE EE 2007
MCQ (Single Correct Answer)
+2
-0.6
A $$100$$ $$kVA$$, $$415V,$$ star connected synchronous machine generates rated open circuit voltage $$415V$$ at a field current of $$15A.$$ The short circuit armature current at a field current of $$10A$$ is equal to the rated armature current. The per unit saturated synchronous reactance is
A
$$1.731$$
B
$$1.5$$
C
$$0.666$$
D
$$0.577$$
GATE EE Subjects
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