A 115 kV three-phase transposed transmission line is composed of 2-ACSR 336,400 cmil, 30/7 Oriole conductor per phase with horizontal configuration: \(D_{12}\) = 7 ft, \(D_{23}\) = 7 ft, \(D_{13}\) =14 ft. The line spacing is measured from the center of the bundled conductors. The distance between the conductors of the bundle is 6 inches. The conductors have a diameter of 0.741 inch and a GMR of 0.02255 ft. Find the capacitance per phase for 20 km of the line in microfarads.
A0.13
B0.2719
C0.2889
D0.2609
#82📜 EE Pre-Board March 2017📘 PowerhouseEasy
In a long transmission line at no load, the receiving end voltage as compared to the sending end voltage is (I) higher, (II) lower, (III) the same.
AI only
BII only
CEither I or II
DIII only
#83📜 EE Pre-Board March 2017📘 PowerhouseEasy
A distributor is designed from the point of view of
Avoltage drop
Bcurrent carrying capacity
Cvoltage drop and current
Dload capacity
#84📜 EE Pre-Board March 2017📘 PowerhouseEasy
The presence of an earth in case of overhead lines
Aincreases the capacitance
Bdecreases the capacitance
Cincreases the inductance
Ddecreases the inductance
#85📜 EE Pre-Board March 2017📘 PowerhouseEasy
A string insulator has 6 units. The voltage across the bottom most unit is 20% of the total voltage. Its string efficiency is
A20%
B60%
C75%
D83.3%
#86📜 EE Pre-Board March 2017📘 PowerhouseEasy
What is the empirical formula to calculate the number of strands?
A3n(n + 2n) + 2
B3n(n + 1) + 2
C3n(n + 1) + 1
D3n(3 + 3n) + 1
#87📜 EE Pre-Board March 2017📘 PowerhouseEasy
When bundled conductors are used in transmission lines, the effective capacitance and inductance will respectively
Adecrease and increase
Bincrease and decrease
Cremain same and increase
Ddecrease and remain same
#88📜 EE Pre-Board March 2017📘 PowerhouseMedium
A 345 kV transmission line has a series impedance of 4 + j60 Ω and a shunt admittance of \(j2 \times 10^{-3}\) S. Using 100 MVA and the line voltage as base values, calculate the per unit shunt admittance of the line.
Aj2.38 pu
Bj3.57 pu
Cj4.76 pu
Dj5.95 pu
#89📜 EE Pre-Board March 2017📘 PowerhouseMedium
The conductors of a three-phase transmission line are arranged in the form of an equilateral triangle with sides of 6 m each. If the conductors are 500 mils in diameter and the line is 25 km long, what is its inductance per phase?
A40 mH
B17.75 mH
C26.62 mH
D35.5 mH
#90📜 EE Pre-Board August 2017📘 PowerhouseMedium
The capacitance between any two conductors of a three-conductor cable, with the third conductor grounded, is 0.6 μF/km. Calculate the capacitance per phase (to neutral) of a 25-km length of the cable.
A30 μF
B15 μF
C7.5 μF
D45 μF
#91📜 EE Pre-Board August 2017📘 PowerhouseEasy
A 100-km transmission line has a 1,200 Ω shunt reactance. What is the per km shunt reactance?
A12 Ω
B120,000 Ω
C1,200 Ω
D120 Ω
#92📜 EE Pre-Board August 2017📘 PowerhouseHard
A short 3Φ transmission line with an impedance of 6 + j8 Ω per phase has sending and receiving end voltages of 120 kV and 110 kV respectively for some receiving end load at a p.f. of 0.9 lagging. Determine the sending end power factor.
A0.88 lagging
B0.90 lagging
C0.84 lagging
D0.93 lagging
#93📜 EE Pre-Board August 2017📘 PowerhouseMedium
A 60 kV, three-phase short transmission line is 16 km long. The line has a per phase series impedance of 0.125 + j0.4375 ohm per km. Determine the transmission efficiency when the line delivers 70 MVA, 0.80 lagging power factor at 64 kV.
A95.9%
B97.6%
C93.8%
D91.4%
#94📜 EE Pre-Board August 2017📘 PowerhouseHard
A three-phase 60 Hz transposed 230 kV transmission line has a horizontal configuration with \(D_{ab} = D\), \(D_{bc} = D\) and \(D_{ac} = 2D\). The line reactance is 0.486 ohm per km. The conductor GMR is 2.0 cm. What is the phase spacing D?
A8 m
B10 m
C12.6 m
D6.3 m
#95📜 EE Pre-Board August 2017📘 PowerhouseMedium
A single-phase, 10-km transmission line has a 16.65 mH total inductance. If the distance between the conductors is 1.0 m, what is the conductor radius?
A2 cm
B1.5 cm
C1 cm
D0.75 cm
#96📜 EE Pre-Board August 2017📘 PowerhouseHard
A 3-phase, 60 Hz, 230 kV transposed transmission line is composed of two 1,272 MCM 54/19 conductors per phase with horizontal configuration. The bundle conductors are 50 cm apart, while the phase spacing between the centers of the bundles is 10 meters. If the GMR of the ACSR conductors is 0.0466 ft, find the inductive reactance in ohm/km/phase of the line.
A0.3775
B0.4386
C0.3292
D0.5054
#97📜 EE Pre-Board August 2017📘 PowerhouseMedium
A short 230 kV transmission line has an impedance of \(10\angle 80^\circ\) Ω. The sending end supplies 150 MW at 230 kV and 82% power factor. What is the voltage at the other end?
A230 kV
B227 kV
C220.3 kV
D224.5 kV
#98📜 EE Pre-Board March 2018📘 PowerhouseHard
A three-phase 60 Hz line has flat horizontal spacing. The conductors have an outside diameter of 3.28 cm with 12 m between conductors. Determine the capacitive reactance of the line to neutral if its length is 125 miles.
A\(1.6 \times 10^{3}\) Ω
B\(202.4 \times 10^{3}\) Ω
C\(25.3 \times 10^{3}\) Ω
D\(16.2 \times 10^{3}\) Ω
#99📜 EE Pre-Board March 2018📘 PowerhouseEasy
The capacitive reactance of a transmission line is 90,000 ohms per kilometer. Find the total capacitive reactance if the transmission line is 50-km long.
