Parameters and Performance of Transmission Lines · Power System Analysis · GATE EE
Start PracticeMarks 1
GATE EE 2023
A 50 Hz, 275 kV line of length 400 km has the following parameters:
Resistance, R = 0.035 $$\Omega$$/km;
Inductance, L = 1 mH/km;
Capacitance, C = 0.0...
GATE EE 2022
The geometric mean radius of a conductor, having four equal strands with each strand of radius r, as shown in the figure below, is
...
GATE EE 2018
In the figure, the voltages are
$${v_1}\left( t \right) = 100\cos \left( {\omega t} \right)$$
$${v_2}\left( t \right) = 100\cos \left( {\omega t + {\p...
GATE EE 2017 Set 2
The normal - $$\pi $$ circuit of a transmission line is shown in the figure.
Impedance $$Z = 100\angle {80^ \circ }$$ and reactance $$\,X = 3300\Ome...
GATE EE 2017 Set 1
A source is supplying a load through a 2-phase, 3-wire transmission system as shown in figure
below. The instantaneous voltage and current in phase-a ...
GATE EE 2014 Set 2
A single phase induction motor draws $$12MW$$ power at $$0.6$$ lagging power. A capacitor is connected in parallel to the motor to improve the power f...
GATE EE 2014 Set 3
In a long transmission line with $$r, l, g$$ and $$𝑐$$ are the resistance, inductance, shunt conductance and capacitance per unit length respectively...
GATE EE 2014 Set 1
The undesirable property of an electrical insulating material is
GATE EE 2013
A single load is supplied by a single voltage source. If the current flowing from the load to the source is $$10\angle - {150^0}$$ A and if the volta...
GATE EE 2011
For enhancing the power transmission in along $$EHV$$ transmission line, the most preferred is to connect a
GATE EE 2011
A nuclear power station of $$500$$ $$MW$$ capacity is located at $$300$$ km away from a load center. Select the most suitable power evacuation transmi...
GATE EE 2010
Consider two buses connected by an impedance of $$\left( {0 + j5} \right)\Omega .$$ The bus $$1$$ voltage is $$100$$$$\angle {30^ \circ }\,\,\,V,$$ an...
GATE EE 2010
Consider a step voltage wave of magnitude $$1$$ pu travelling along a loss less transmission line that terminates in a reactor. The voltage magnitude ...
GATE EE 2009
For a fixed value of complex power flow in a transmission line having a sending end voltage $$V$$, the real power loss will be proportional to
GATE EE 2008
An extra high voltage transmission line of length $$300$$ km can be approximate by a lossless line having propagation constant $$\beta = 0.00127$$ ra...
GATE EE 2007
Consider the transformer connections in a part of a power system shown in the figure. The nature of transformer connections and phase shifts are indic...
GATE EE 2007
Consider a bundled conductor of an overhead line consisting of three identical sub-conductors placed at the corners of an equilateral triangle as show...
GATE EE 2006
A $$400$$ V, $$50$$ Hz, three phase balanced source supplies power to a star connected load whose rating is $$12\sqrt 3 $$ kVA, $$0.8$$ pf(lag). The r...
GATE EE 2006
The concept of an electricity short, medium and long line is primarily based on the
GATE EE 2005
The insulation strength of an EHV transmission line is mainly governed by
GATE EE 2004
The phase sequence of the $$3$$-phase system shown in figure is
...
GATE EE 2004
The rated voltage of a $$3$$-phase power system is given as
GATE EE 2004
Total instantaneous power supplied by a $$3$$-phase ac supply to a balanced $$R$$-$$L$$ load is
GATE EE 2003
Bundled conductors are mainly used in high voltage overhead transmission lines to
GATE EE 2003
A $$3$$-phase, $$11$$-$$kV$$ generator feeds power to a constant power unity power factor load of $$100$$ $$MW$$ through a $$3$$-phase transmission li...
GATE EE 2002
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 centers...
GATE EE 2002
A long wire composed of a smooth round conductor runs above and parallel to the ground (assumed to be a large conducting plane). A high voltage exists...
GATE EE 2001
A lossless radial transmission line with surge impedance loading
GATE EE 1999
The load carrying capability of a long AC transmission line is
GATE EE 1999
Corona losses are minimized when
GATE EE 1999
An overhead line having a surge impedance of $$400$$$$\Omega $$ is connected in series with an underground cable having a surge impedance of $$100$$$$...
GATE EE 1998
Series capacitive compensation in $$EHV$$ transmission lines is used to
GATE EE 1998
The reflection coefficient for the transmission line shown in figure at $$P$$ is
...
GATE EE 1996
For a $$500$$ Hz frequency excitation, a $$50$$ km short power line will be modeled as
GATE EE 1995
The insulation resistance of a cable of length $$10$$ km is $$1$$ $$M\Omega $$. For a length of $$100$$ km of the same cable, the insulation resistanc...
GATE EE 1995
The surge impedance of a $$400$$ km long overhead transmission line is $$400$$ $$\Omega $$. For a $$200$$ km length of the same line, the surge impeda...
GATE EE 1995
The insulation level of a $$400$$ kV, EHV overhead transmission line is decided on the basis of
GATE EE 1994
In a $$400$$ kV network, $$360$$ kV is recorded at a $$400$$ kV bus. The reactive power absorbed by a shunt reactor rated for $$50$$ MVAR, $$400$$ kV ...
GATE EE 1993
A three phase overhead transmission line has its conductors horizontally spaced with spacing between adjacent conductors equal to 'd'. If now the cond...
GATE EE 1992
The selection of size of conductors for a distributor in a distribution system is governed by
GATE EE 1992
The inductance of a power transmission line increases with
Marks 2
GATE EE 2018
Consider the two bus power system network with given loads as shown in the figure. All
the values shown in the figure are in per unit. The reactive po...
GATE EE 2017 Set 2
Consider an overhead transmission line with $$3$$-phase, $$50$$ $$Hz$$ balanced system with conductors located at the vertices of an equilateral trian...
GATE EE 2017 Set 2
A 3-phase 50 Hz generator supplies power of 3 MW at 17.32 kV to a balanced 3-phase inductive load through an overhead line. The per phase line resista...
GATE EE 2017 Set 1
A load is supplied by a $$230$$ $$V,$$ $$50$$ $$Hz$$ source. The active power $$P$$ and the reactive power $$Q$$ consumed by the load are such that $$...
GATE EE 2016 Set 1
A three-phase cable is supplying $$800$$ kW and $$600$$ kVAr to an inductive load. It is intended to supply an additional resistive load of $$100$$ kW...
GATE EE 2016 Set 1
A single-phase transmission line has two conductors each of 10 mm radius. These are fixed at a center-to-center distance of 1 m in a horizontal plane....
GATE EE 2015 Set 2
A composite conductor consists of three conductors of radius $$R$$ each. The conductors are arranged as shown below. The geometric mean radius (GMR) (...
GATE EE 2014 Set 2
The horizontally placed conductors of a single phase line operating at $$50$$ $$Hz$$ are having outside diameter of $$1.6$$ cm, and the spacing betwee...
GATE EE 2014 Set 3
The complex power consumed by a constant-voltage load is given by $$\left( {{P_1} + {J_{q1}}} \right).\,\,$$ Where, $$\,1\,\,kW \le \,\,{P_1} \le \,\,...
GATE EE 2014 Set 3
For a $$400$$ $$km$$ long transmission line, the series impedance is $$(0.0 + j0.5)$$ $$\Omega /km$$ and the shunt admittance is $$(0.0 + j5.0)$$ $$\...
GATE EE 2014 Set 1
A distribution feeder of $$1$$ $$km$$ length having resistance, but negligible reactance, is fed from both the ends by $$400$$ $$V,$$ $$50$$ $$Hz$$ ba...
GATE EE 2014 Set 1
A two bus power system shown in figure supplies load of $$1.0+j0.5$$ $$p.u$$
The value of $${V_1}$$ in $$p.u$$ and $${\delta _2}$$ respectively are...
GATE EE 2012
For the system shown below, SD1 and SD2 are complex power demands at bus $$1$$ and bus $$2$$ respectively. If $$\left| {{V_2}} \right| = 1$$ pu, the V...
GATE EE 2011
A lossy capacitor $${C_x}$$, rated for operation at $$5$$ $$kV,$$ $$50$$ $$Hz$$ is represented by an equivalent circuit with an ideal capacitor $${C_p...
GATE EE 2010
A $$50$$ $$Hz$$ synchronous generator is initially connected to a long lossless transmission line which is open circuited at the receiving end. With t...
GATE EE 2010
Consider a three-phase, $$50Hz,$$ $$11$$ $$kV$$ distribution system. Each of the conductors is suspended by an insulator string having two identical p...
GATE EE 2010
Consider a three-core, three phase, $$50$$ $$Hz$$, $$11$$ $$kV$$ cable whose conductors are denoted as $$R, Y$$ and $$B$$ in the figure. The inter-pha...
GATE EE 2009
Match the items List-$${\rm I}$$ (To) with the items in List-$${\rm II}$$ (Use) and select the correct answer using the codes given below the lists.
...
GATE EE 2008
A lossless transmission line having Surge Impedance Loading $$(SIL)$$ of $$2280$$ $$MW.$$ A Series capacitive compensation of $$30$$% is emplaced. T...
GATE EE 2007
Single line diagram of a $$4$$-bus single source distribution system is shown below. Branches $${e_1},\,\,$$ $${e_2},\,\,$$ $${e_3}\,\,$$ and $${e_4}\...
GATE EE 2007
$$230$$ $$V$$ (phase) $$50$$ Hz, three-phase, $$4$$-wire, system has a sequence $$ABC$$. A unity power-factor load of $$4$$ kW is connected between ph...
GATE EE 2007
The total reactance and total susceptance of a lossless overhead $$EHV$$ line, operating at $$50$$ $$Hz,$$ are given by $$0.045$$ pu and $$1.2$$ pu re...
GATE EE 2006
The $$A, B, C, D$$ constant of a $$220$$ $$kV$$ line are:
$$A = D = 0.94\,\angle \,10,\,\,\,B = 130\,\angle \,730,\,\,\,C = 0.001\,\angle \,900.\,\,$...
GATE EE 2005
At an industrial sub-station with a $$4$$ $$MW$$ load, a capacitor of $$2$$ MVAR is installed to maintain the load power factor at $$0.97$$ lagging. I...
GATE EE 2004
A lightning stroke discharges impulse current of $$10$$ kA (peak) on a $$400$$ kV transmission line having surge impedance of $$250\,\Omega $$. The ma...
GATE EE 2004
A $$110$$ $$kV,$$ single core coaxial, XLPE insulated power cable delivering power at $$50$$ $$Hz,$$ has a capacitance of $$125$$ $$nF/km.$$ If the di...
GATE EE 2004
A $$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.$$ Ign...
GATE EE 2004
The generalized circuit constants of a $$3$$-phase, $$220$$ $$kV$$ rated voltage, medium length transmission line are $$A = D = 0.936 + j\,0.016 = 0.9...
GATE EE 2003
The ABCD parameters of a $$3$$-phase overhead transmission line are $$\,A = D = 0.9\angle {0^ \circ }.\,\,B = 200\,\angle {90^ \circ }\,\,\Omega \,\,\...
GATE EE 2003
A surge of 20 kV magnitude travels along a lossless cable towards its junction with two identical lossless overhead transmission lines. The inductance...
GATE EE 2003
A dc distribution system is shown in figure with load currents as marked. The two ends of the feeder are fed by voltage sources such that $${V_P} - {V...
GATE EE 2003
A balanced delta connected load of $$\left( {8 + j6} \right)\Omega $$ per phase is connected to a $$400$$ $$V$$, $$50$$ $$Hz$$, $$3-$$phase supply lin...
GATE EE 2001
The conductors of a $$10$$ km long, single phase, two wire line are separated by a distance of $$1.5$$ m. The diameter of each conductor is $$1$$ cm. ...
GATE EE 2001
Consider the model shown in figure of a transmission line with a series capacitor at its mid-point. The maximum voltage on the line is at the location...
GATE EE 2000
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 EE 2000
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 volt...
GATE EE 1999
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. ...
GATE EE 1999
A single phase AC distributor supplies two single phase loads as shown in figure. The voltage drop from A to C is
...
GATE EE 1999
$$A$$ $$220$$ kV, $$20$$ km long, $$3$$-phase transmission line has the following $$A, B, C, D$$ constants. $$A=D=0.96$$$$\angle {3^0},$$ $$\,B = 55\a...
GATE EE 1999
For a single phase overhead line having solid copper conductors of diameter $$1$$ cm, spaced $$60$$ cm between centers, the inductance in $$mH/km$$ is
GATE EE 1998
A cable has the following characteristics. $$L = 0.201\,\,\mu H/m\,\,$$ and $$\,C = 196.2\,pF/m.\,$$ The velocity of wave propagation through the cabl...
GATE EE 1998
A shunt reactor of $$100$$ MVAR is operated at $$98$$% of its rated voltage and $$96$$% of its rated frequency. The reactive power absorbed by the rea...
GATE EE 1996
For equilateral spacing of conductors of an untransposed $$3$$-phase line, we have
GATE EE 1995
The rated load of an underground cable is always _______its natural load.
GATE EE 1994
The charging current of a $$400$$ kV transmission line is more than that of a $$220$$ kV line of the same length.
GATE EE 1994
Consider a three-phase, $$50$$ $$Hz$$, $$11$$ $$kV$$ distribution system. Each of the conductors is suspended by an insulator string having two identi...
Marks 5
GATE EE 2003
In a transmission line each conductor is at $$20$$ $$kV$$ and is supported by a string of $$3$$ suspension insulators. The air capacitance between eac...
GATE EE 2002
A long lossless transmission line has a unity power factor (UPF) load at the receiving end and an ac voltage source at the sending end. The parameters...
GATE EE 2001
A 132 kV transmission line AB is connected to a cable BC. The characteristic impedances of the overhead line and the cable are 400$$\Omega $$ and 80$$...
GATE EE 2000
A $$275$$ $$kV,$$ $$3$$-phase, $$50$$ $$Hz,$$ $$400$$ $$km$$ lossless line has following parameters:
$$x=0.05$$ $$ohms/km,$$ line charging susceptance...
GATE EE 1999
A 66 kV, 3-phase, 50 Hz, 150 km long overhead transmission line is open circuited at the receiving end. Each conductor has a resistance of 0.25$$\Omeg...
GATE EE 1999
A 6.6 kV, 50 Hz single core lead sheathed cable has the following data:
Conductor diameter: 1.5 cm, length: 4 km. Internal diameter of the sheath : 3 ...
GATE EE 1998
Each conductor of a $$33$$ $$kV,$$ $$3$$ phase system is suspended by a string of three similar insulators. The ratio of shunt capacitance to mutual c...
GATE EE 1997
A factory draws $$100$$ kW at $$0.7$$ p.f. lagging from a $$3$$-phase, $$11$$ kV supply. It is desired to the p.f. to $$0.95$$ lagging using series ca...
GATE EE 1994
The increase in resistance due to non-uniform distribution of current in a conducto $$r$$ is known as _______effect