Power systems miscellaneous
- An RLC series circuit remains predominantly inductive
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Resonance frequency for series RLC circuit,
ω0 = 1 √LC
If ω > ω0, and ωL > 1/ωC, thenZ = R + j 
ωL - 1 
ωC
will be inductive.Correct Option: C
Resonance frequency for series RLC circuit,
ω0 = 1 √LC
If ω > ω0, and ωL > 1/ωC, thenZ = R + j ωL - 1 ωC
will be inductive.
- For reducing tower footing resistance, it is better to use
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Since the tower footing resistance is a function of the soil resistivity and critical breakdown gradient of the soil, therefore chemical treatment can be the option. But practically this is not feasible as it needs regular check up about soil conditions at each and every tower which runs is several miles. Hence we use only ground rod and counterpoise only.
Correct Option: C
Since the tower footing resistance is a function of the soil resistivity and critical breakdown gradient of the soil, therefore chemical treatment can be the option. But practically this is not feasible as it needs regular check up about soil conditions at each and every tower which runs is several miles. Hence we use only ground rod and counterpoise only.
- Critical voltage limit of a transmission line is increased by
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NA
Correct Option: A
NA
- The leakage resistance of a 50 km long cable is 1 MΩ. For a 100 km long cable it will be
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Leakage Resistance,
R = ρ In R 2πl r R ∝ 1 l
where, l = length of the cable∴ R1 = l2 R2 l1 R2 = R1 l1 = 1 mΩ 50 l2 100
= 0.5MωCorrect Option: D
Leakage Resistance,
R = ρ In R 2πl r R ∝ 1 l
where, l = length of the cable∴ R1 = l2 R2 l1 R2 = R1 l1 = 1 mΩ 50 l2 100
= 0.5Mω
- A loss less line terminated with its surge impedance has
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NA
Correct Option: A
NA
