Introduction and Transmission Line Basics || Power System || GATE EE || PYQS(2000-2025)

The concept of an electrically short, medium, and long line is primarily based on the

( GATE 2006 || EE || MCQ || 1 MARK)

The ABCD parameters of a 3-phase overhead transmission line are: A = D = 0.9∠0°; B = 200 200∠90°Ω and 0.95 × 10–3∠90°S. At no-load condition, a shunt inductive reactor is connected at the receiving end of the line to limit the receiving-end voltage to be equal to the sending-end voltage. The ohmic value of the reactor is

(GATE 2003 || EE || MCQ || 2 MARKS)

A transmission line has equal voltages at the two ends, maintained constant by two sources. A third source is to be provided to maintain constant voltage (equal to end voltages) at either the midpoint of the line or at 75% of the distances from the sending end. Then the maximum power transfer capabilities of the line in the original case and the other two cases respectively will be in the following rations.

(GATE 2000 || EE || MCQ || 2 MARKS)

The corona loss on a particular system at 50 Hz is 1 kW/km per phase. The corona loss at 60 Hz would be

(GATE 2000 || EE || MCQ || 2 MARKS)

A three-phase 50 Hz, 400 kV transmission line is 300 km long. The line inductance is 1 mH/km per phase and the capacitance is 0.01 μF/km per phase. The line is under open circuit condition at the receiving end and energized with 400 kV at the sending end, the receiving end line voltage in kV (round off two decimal places) will be ___________.

(GATE 2019 || EE || NAT || 2 MARKS)

A single-phase transmission line has two conductors each of 10 mm radius. These are fixed at a centre-to-centre distance of 1 m in a horizontal plane. This is now converted to a three-phase transmission line by introducing a third conductor of the same radius. This conductor is fixed at an equal distance D from the two single-phase conductors. The three-phase line is fully transposed. The positive sequence inductance per phase of the three-phase system is to be 5% more than that of the inductance per conductor of the single-phase system. The distance D, in meters, is ____________.

(GATE 2016 || EE || NAT || 2 MARKS)

A composite conductor consists of three conductors of radius R each. The conductors are arranged as shown below. The geometric mean radius (GMR) (in cm) of the composite conductor is kR. The value of k is __________.

(GATE 2015 || EE || MCQ || 2 MARKS)

The horizontally placed conductors of a single-phase line operating at 50 Hz are having outside diameter of 1.6 cm, and the spacing between centres of the conductors is 6 m. The permittivity of free space is 8.854 × 10–12 F/m. The capacitance to ground per kilometre of each line is

(GATE 2014 || EE || MCQ || 2 MARKS)

A single-phase transmission line and a telephone line are both symmetrically strung one below the other, in horizontal configurations, on a common tower. The shortest and longest distances between the phase and telephone conductors are 2.5 m and 3 m respectively. The voltage (volt/km) induced in the telephone circuit, due to 50 Hz current of 100 amps in the power circuit is

(GATE 2006 || EE || MCQ || 2 MARKS)

Consider a long, two-wire line composed of solid round conductors. The radius of both conductors is 0.25 cm and the distance between their centres is 1 meters. If this distance is doubled, then the inductance per unit length.

(GATE 2002 || EE || MCQ || 1 MARK)