1
GATE EE 2010
MCQ (Single Correct Answer)
+2
-0.6
The L-C circuit shown in the figure has an inductance $$L=1mH$$ and a capacitance $$C = 10\mu F.$$

The $$L$$-$$C$$ circuit $$Q.13$$ is used to commutate a thyristor, which is initially carrying a current of $$5A$$ as shown in the figure below. The values and initial conditions of $$L$$ and $$C$$ are the same as in $$Q.13.$$ The switch is closed at $$t = 0.$$ If the forward drop is negligible, the time taken for the device to turn off is

GATE EE 2010 Power Electronics - Choppers and Commutation Techniques Question 33 English
A
$$52\mu s$$
B
$$156\mu s$$
C
$$312\mu s$$
D
$$26\mu s$$
2
GATE EE 2010
MCQ (Single Correct Answer)
+2
-0.6
A $$50$$ $$Hz$$ synchronous generator is initially connected to a long lossless transmission line which is open circuited at the receiving end. With the field voltage held constant, the generator is disconnected from the transmission line. Which of the following may be said about the steady state terminal voltage and field current of the generator?
A
The magnitude of terminal voltage decreases, and the field current does not change.
B
The magnitude of terminal voltage increases, and the field current does not change.
C
The magnitude of terminal voltage increases, and the field current increases.
D
The magnitude of terminal voltage does not change, and the field current decreases.
3
GATE EE 2010
MCQ (Single Correct Answer)
+2
-0.6
A three-phase, $$33$$ kV oil circuit breaker is rated $$1200$$ A, $$2000$$ MVA, $$3$$s. The symmetrical breaking current is
A
$$1200$$ A
B
$$3600$$ A
C
$$35$$ kA
D
$$104.8$$ kA
4
GATE EE 2010
MCQ (Single Correct Answer)
+2
-0.6
Consider a stator winding of an alternator with an internal high resistance ground fault. The currents under the fault condition are as shown in the figure. The winding is protected using a differential current scheme with current transformers of ratio $$400/5$$ $$A$$ as shown. The current through the operating coil is GATE EE 2010 Power System Analysis - Switch Gear and Protection Question 9 English
A
$$0.1875$$ $$A$$
B
$$0.2$$ $$A$$
C
$$0.375$$ $$A$$
D
$$60$$ $$kA$$