1
GATE EE 1999
MCQ (Single Correct Answer)
+1
-0.3
An overhead line having a surge impedance of $$400$$$$\Omega $$ is connected in series with an underground cable having a surge impedance of $$100$$$$\Omega $$. If a surge of $$50$$ $$kV$$ travels from the line end towards the cable junctions, the value of the transmitted voltage wave at the junction is
A
$$30$$ kV
B
$$20$$ kV
C
$$80$$ kV
D
$$-30$$ kV
2
GATE EE 1999
MCQ (Single Correct Answer)
+2
-0.6
A 3-phase, 11 kV, 50 Hz, 200 kW load has a power factor of 0.8 lag. A delta connected 3-phase capacitor is used to improve the power factor to unity. The capacitance power phase of the capacitor in micro-farads is
A
3.948
B
1.316
C
0.439
D
11.844
3
GATE EE 1999
MCQ (Single Correct Answer)
+1
-0.3
Corona losses are minimized when
A
Conductor size is reduced.
B
Smooth conductor is reduced.
C
Sharp points are provided in the line hardware.
D
Current density in conductors is reduced.
4
GATE EE 1999
Subjective
+5
-0
Determine the magnitudes of the symmetrical components ($${{{\rm I}_{R1}},\,{{\rm I}_{R2}}\,}$$ and $${{{\rm I}_{R0}}}$$) of the currents in a three phase (RYB) three wire system, when a short circuit occurs between R and Y phase wires, the fault current being 100 A.