# A low-loss transmission line has

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A low-loss transmission line has  R<<ωL; G<<ωC.

## Related questions

The power loss in a transmission line depends on (a) current in the line. (b) resistance of the line. (c) length of the line. (d) All of the above

A loss less transmission line having Surge Impedance Loading (SIL) of 2280 MW is provided with a uniformly distributed series capacitive compensation of 30%. Then, SIL of the compensated transmission line will be (A) 1835 MW (B) 2280 MW (C) 2725 MW (D) 3257 MW

The input impedance of a short circuited loss less transmission line of characteristic impedance 50 Ohm is

The corona loss of a 3-phase transmission line is 100 kW at 60 kV/phase and 25 kW at 50 kV/phase. The disruptive critical voltage is (A) 40 kV (B) 43.6 kV (C) 49.6 kV (D) 50 kV

A 100 km long transmission line is loaded at 110 kV.if the loss of line is 5 MW and the load is 150 MVA, the resistance of the line is?

The impedance Z offered by transmission line for a travelling wave which damps out the low frequency oscillation rapidly is also called

lf a travelling-wave travelling along a loss-less overhead line does not result in any reflection after it has reached the far end, then the far end of the line is

A loss less line terminated with its surge impedance has

A loss less line of characteristic impedance Z0 is terminated in pure reactance of –jZ0 value. VSWR is  (1) 10 (2) 2 (3) 1 (4) Infinity

A long transmission line has considerable ……………….. effect. A) series capacitance B) shunt capacitance C) series inductance D) shunt inductance

An overhead transmission line has a span of 260 m. The weight of the conductor is 0.68 kg/m. The maximum allowable tension in the line is 1550 kg. Maximum sag of the line should be (a) 5.8 m (b) 4.6 m (c) 2.7 m (d) 3.7 m

An 800 kV transmission line has a maximum power transfer capacity of P. If it is operated at 400 kV with the series reactance unchanged, the new maximum power transfer capacity is approximately (A) P (B) 2P (C) P / 2 (D) P / 4

A transmission line has 1 P.0 impedance on a base of 11 KV, 100 MVA. On a base of 55 KV. it will have a P.0 impedance of

A transmission line of 200 km has a certain A, B, C and D parameters. If the length is reduced to 60 km

A Transmission line conductor has been suspended freely from two towers and has taken the form of a catenary that has c = 487.68m. The span between the two towers is 152 m, and the weight of the conductor is 1160 kg/km. Calculate the length of the conductor.  (A) 487.68 m (B) 152.614 m (C) 5.934 m (D) 11.9 m

The line conductor of a transmission line has an overall diameter of 19.53 mm, weight 0.844 kg/m and an ultimate breaking strength of 7950 kg. If the factor of safety is to be 2, when conductor has an ice of 1 kg/m and a horizontal wind pressure of 1.5 kg/m. What is the vertical sag, corresponding to this loading for a 300 m span level supports?

An overhead transmission line has a span of 240m between level supports. What is the maximum sag if the conductor weight 727 kg/km and has a breaking strength of 6880 kg? Allow the factor of safety of 2. Neglecting wind and ice loading.

A three phase overhead transmission line has its conductors horizontally spaced with spacing between adjacent conductors equal to 'd'. if now the conductors of the line are rearranged to form and the equilateral triangle of sides equal to 'd' then?

The magnitude of the open-circuit and short circuit input impedance of a transmission line are 100 ohm and 25 ohm respectively. The characteristic impedance of line is:  (1) 25 ohm (2) 50 ohm (3) 75 ohm (4) 100 ohm

What is the difference between a line voltage and low voltage control system?

A 6-pole, 50Hz, 3-φ induction motor is running at 950 r.p.m. and has Cu loss of 5kW. The rotor input is (a) 10 kW (b) 95 kW (c) 100 kW (d) 9.5 kW

A single-phase transformer has no-load loss of 64 W, as obtained from an open circuit test. When a short-circuit test is performed on it with 90% of the rated currents flowing in its both LV and HV windings, he measured loss is 81 W. The transformer has maximum efficiency when operated at  (A) 50.0% of the rated current (B) 64.0% of the rated current (C) 80.0% of the rated current (D) 88.8% of the rated current

A 40 kVA transformer has a core loss of 400 W and a full load copper loss of 800 W. The proportion of full load at maximum efficiency is

An 8-pole, 50Hz, three-phase induction motor is running at 705rpm and has a rotor copper loss of 5kW. Its rotor input is (A) 5.06 kW (B) 0.3 kW (C) 100 kW (D) 83.33 kW

A transformer has maximum efficiency at 3/4 full load. The ratio of its iron losses and full load copper loss is : -  a) 16/9 b) 4 / 3 c) 3/4 d) 9 /16

A ferrite core has less eddy current loss than an iron core because?

A low noise amplifier has an effective noise temperature of 50 k. The absolute noise figure is

A generating station which has a high investment cost and low operating cost is usually operated as  A) Peak load station B) Spinning reserve station C) Base load station D) None of the above

Corona loss in transmission lines can be reduced by (A) using small diameter conductors (B) using bundled conductors (C) using less spacing between conductors (D) increasing the transmission line voltage

A 50Ω transmission line is terminated in an impedance of 20-j50. What will be the reflection coefficient? A) 0.69 B) 1.69 C) 6.9 D) 16.9

A synchronous condenser is used at the receiving end of a transmission line for (A) supplying lagging kVA (B) voltage control (C) frequency control (D) maintaining a higher voltage than at the sending end

A single-line-to-ground fault on a overhead transmission line creates (A) voltage sag (B) voltage swell (C) over voltage (D) voltage flicker

The standing wave ratio of a 75 Ω transmission line used to feed a 300 Ω resistive load will be _____.

For a transmission line open circuit and short circuit impedances are 20 Ω and 5 Ω. Then characteristic impedance is: (1) 100 Ω (2) 50 Ω (3) 25 Ω (4) 10 Ω

If diameter of each conductor of a transmission line is ‘d’, then the diameter of n-layer stranded conductor will be (a) (2n – 1) d (b) (2n + 1) d (c) (3n – 1) d (d) (3n + 1) d

A transmission line to be reciprocal, the condition is (a) A = D (b) AC – BD = 1 (c) AD – BC = 1 (d) AB – CD = 1

A 20-MVA, 6.6-kV, 3-phase alternator is connected to a 3-phase transmission line. The per unit positive-sequence, negative-sequence and zero-sequence impedances of the alternator are j0.1, j0.1 and j0.04 respectively. The neutral of the alternator is connected to ground through an inductive reactor of j0.05 p.u. The per unit positive-, ... The voltage of the alternator neutral with respect to ground during the fault is  (A) 513.8 V (B) 889.9 V (C) 1112.0 V (D) 642.2 V

Choose two appropriate auxiliary components of a HVDC transmission system from the following P. D.C line inductor Q. A.C line inductor R. Reactive power sources S. Distance relays on D.C line T. Series capacitance on A.C. line  (A) P and Q (B) P and R (C) Q and S (D) S and T

A 800 kV transmission line is having per phase line inductance of 1.1 mH/km and per phase line capacitance of 11.68 nF/km. Ignoring the length of the line, its ideal power transfer capability in MW is (A) 1204 MW (B) 1504 MW (C) 2085 MW (D) 2606 MW

A generator is connected through a 20 MVA, 13.8/138 kV step down transformer, to a transmission line. At the receiving end of the line a load is supplied through a step down transformer of 10 MVA, 138/69 kV rating. A 0.72 pu. load, evaluated on load side transformer ratings as base values , is supplied from the above system. For system base values of 10 MVA and 69 kV in load circuit, the value of the load (in per unit) in generator will be (A) 36 (B) 1.44 (C) 0.72 (D) 0.18

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 (A) 4.81 (B) 3.56 (C) 2.29 (D) 1.27

Voltages phasors at the two terminals of a transmission line of length 70 km have a magnitude of 1.0 per unit but are 180 degree out of phase. Assuming that the maximum load current in the line is 1/5th of minimum 3-phase fault current. Which one of the following transmission line protection schemes ... pick up at 1.25 times the maximum load current (C) Pilot relaying system with directional comparison scheme (D) Pilot relaying system with segregated phase comparison scheme

A transmission line is operating with a Phase shift of 80° between two ends. If the load is suddenly increased A) The phase displacement will increase B) The phase displacement will decrease C) The phase displacement will not change D) The surge impedance will increase

To increase power transfer capability of a long transmission line, we should:  (1) Increase line resistance (2) Increase transmission voltage (3) Decrease line reactance (4) Both (2) & (3)