1
GATE EE 2010
+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

A
$$52\mu s$$
B
$$156\mu s$$
C
$$312\mu s$$
D
$$26\mu s$$
2
GATE EE 2009
+2
-0.6
In the chopper circuit shown, the main thyristor $$\left( {{T_M}} \right)$$ is operated at a duty ratio of $$0.8$$ which is much larger than the commutation interval. If the maximum allowable reapplied $${{dV} \over {dt}}$$ on $${T_M}$$ is $$50$$ $$V/\mu s,$$
what should be the theoretical minimum value of $${C_1}?$$. Assume current ripple through $${L_0}$$ to be negligible.
A
$$0.2\,\,\mu \,F$$
B
$$0.02\,\,\mu \,F$$
C
$$2\,\,\mu \,F$$
D
$$20\,\,\mu \,F$$
3
GATE EE 2008
+2
-0.6
In the circuit shown in the figure, the switch is operated at a duty cycle of $$0.5.$$ A large capacitor current is connected across the load. The inductor current is assumed to be continuous.

The average voltage across the load and the average current through the diode will respectively be

A
$$10$$ $$V,$$ $$2A$$
B
$$10$$ $$V,$$ $$8A$$
C
$$40$$ $$V,$$ $$2A$$
D
$$40$$ $$V,$$ $$8A$$
4
GATE EE 2007
+2
-0.6
The circuit in the figure is current commutated $$dc$$ $$-$$ $$dc$$ chopper where, $$T{h_M}$$ is the main $$SCR$$ and $$T{h_AUX}$$ is the auxiliary $$SCR$$. The load current is constant at $$10$$ $$A.$$
$$T{h_M}$$ is $$ON$$
$$T{h_AUX}$$ is trigged at $$t=0.$$ $$T{h_M}$$ is turned $$OFF$$ between.
A
$$0{\mkern 1mu} {\mkern 1mu} \mu s < t \le 25{\mkern 1mu} {\mkern 1mu} \mu s$$
B
$$25{\mkern 1mu} {\mkern 1mu} \mu s < t \le 50{\mkern 1mu} {\mkern 1mu} \mu s$$
C
$$50{\mkern 1mu} {\mkern 1mu} \mu s < t \le 75{\mkern 1mu} {\mkern 1mu} \mu s$$
D
$$75{\mkern 1mu} {\mkern 1mu} \mu s < t \le 100{\mkern 1mu} {\mkern 1mu} \mu s$$
GATE EE Subjects
Electromagnetic Fields
Signals and Systems
Engineering Mathematics
General Aptitude
Power Electronics
Power System Analysis
Analog Electronics
Control Systems
Digital Electronics
Electrical Machines
Electric Circuits
Electrical and Electronics Measurement
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