1
GATE EE 2007
MCQ (Single Correct Answer)
+1
-0.3
A single phase full $$-$$ wave half $$-$$ controlled bridge converter feeds an inductive load. The two $$SCR's$$ in the converter are connected to a common $$DC$$ bus. The converter has to have a free wheeling diode
A
because the converter inherently does not provide for free - wheeling
B
because the converter does not provide for free - wheeling for high values of triggering angles
C
or else the free - wheeling action of the converter will cause shorting of the $$AC$$ triggering angles
D
or else if a gate pulse to one of the $$SCR$$s is missed, it will subsequently cause a high load current in the other $$SCR$$.
2
GATE EE 2007
MCQ (Single Correct Answer)
+1
-0.3
A single $$-$$ phase fully controlled thyristor bridge $$ac$$ $$-$$ $$dc$$ converter is operating at a firing angle of $${25^ \circ }$$ and an overlap angle of $${10^ \circ }$$ constant $$dc$$ output current of $$20$$ $$A$$. The fundamental power factor (displacement factor) at input $$ac$$ mains is
A
$$0.78$$
B
$$0.827$$
C
$$0.866$$
D
$$0.9$$
3
GATE EE 2007
MCQ (Single Correct Answer)
+2
-0.6
The total reactance and total susceptance of a lossless overhead $$EHV$$ line, operating at $$50$$ $$Hz,$$ are given by $$0.045$$ pu and $$1.2$$ pu respectively. If the velocity of wave propagation is $$3\,\, \times \,\,{10^5}$$ km/s, then the approximate length of line is
A
$$122$$ $$km$$
B
$$172$$ $$km$$
C
$$222$$ $$km$$
D
$$272$$ $$km$$
4
GATE EE 2007
MCQ (Single Correct Answer)
+1
-0.3
Two regional system, each having several synchronous generators and loads are interconnected by an ac line and a HVDC link as shown in the figure. Which of the following statements is true in the steady state: GATE EE 2007 Power System Analysis - High Voltage Dc Transmission Question 3 English
A
Both regions need not have the same frequency
B
The total power flow between the regions (Pac + Pdc) can be changed by controlling the HVDC converters alone
C
The power sharing between the ac line and the HVDC link can be changed by controlling the HVDC converters alone.
D
The directions of power flow in the HVDC link (Pdc) cannot be reversed.
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