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Recent activity in Power Systems
0
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0
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1
GATE2016235
The $z$parameters of the two port network shown in the figure are $z_{11}=40\Omega, z_{12}=60\Omega, z_{21}=80\Omega$ and $z_{22}=100\Omega$. The average power delivered to $R_{L}=20\Omega$, in watts, is ________.
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Feb 28, 2017
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Power Systems
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1.5k
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gate2016ee2
averagepower
networkanalysis
0
votes
0
answers
2
GATE2016236
In the balanced $3$phase, $50$ Hz, circuit shown below, the value of inductance $(L)$ is $10$ mH. The value of the capacitance $(C)$ for which all the line currents are zero, in millifarads, is ___________.
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Feb 28, 2017
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Power Systems
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piyag476
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gate2016ee2
balancedsystem
line
currents
+1
vote
0
answers
3
GATE2016238
The single line diagram of a balanced power system is shown in the figure. The voltage magnitude at the generator internal bus is constant and $1.0$ p.u. The p.u. reactances of different components in the system are also shown in the figure ... can be transferred during the prefault condition to the maximum real power that can be transferred under the faulted condition is _________.
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Feb 28, 2017
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Power Systems
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piyag476
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1.5k
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gate2016ee2
singlelinediagram
threephasefault
prefaultcondition
0
votes
0
answers
4
GATE2016240
At no load condition, a $3$phase, $50$ Hz, lossless power transmission line has sendingend and receivingend voltages of $400$ kV and $420$ kV respectively. Assuming the velocity of traveling wave to be the velocity of light, the length of the line, in km, is ____________.
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Feb 28, 2017
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Power Systems
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piyag476
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1.5k
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gate2016ee2
losslesspowertransmissionline
travelingwave
0
votes
0
answers
5
GATE2016241
The power consumption of an industry is $500$ kVA, at $0.8$ p.f. lagging. A synchronous motor is added to raise the power factor of the industry to unity. If the power intake of the motor is $100$ kW, the p.f. of the motor is ___________.
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Feb 28, 2017
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Power Systems
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piyag476
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1.5k
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gate2016ee2
synchronousmotor
powerfactor
powerintake
0
votes
0
answers
6
GATE2016244
A singlephase, $2$ kVA, $100/200$ V transformer is reconnected as an autotransformer such that its $kVA$ rating is maximum. The new rating, in $kVA$, is ______.
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Feb 28, 2017
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Power Systems
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piyag476
(
1.5k
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gate2016ee2
autotransformer
rating
0
votes
0
answers
7
GATE2016251
Three singlephase transformers are connected to form a deltastar threephase transformer of $110$ kV/ $11$ kV. The transformer supplies at $11$ kV a load of $8$ MW at $0.8$ p.f. lagging to a nearby plant. Neglect the transformer losses. The ratio of phase currents in delta side to star side is $1 : 10\sqrt{3}$ $10\sqrt{3} : 1$ $1 : 10$ $\sqrt{3} : 10$
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Feb 28, 2017
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Power Systems
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piyag476
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1.5k
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gate2016ee2
deltastarconnections
transformerlosses
0
votes
0
answers
8
GATE2016253
Two identical unloaded generators are connected in parallel as shown in the figure. Both the generators are having positive, negative and zero sequence impedances of $j0.4$ p.u., $j0.3$ p.u. and $j0.15$ p.u., respectively. If the prefault voltage is $1$ p.u., for a linetoground $(LG)$ fault at the terminals of the generators, the fault current, in p.u., is ___________.
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Feb 28, 2017
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Power Systems
by
piyag476
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1.5k
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gate2016ee2
sequenceimpedences
prefaultvoltage
0
votes
0
answers
9
GATE2016254
An energy meter, having meter constant of $1200$ revolutions/kWh, makes $20$ revolutions in $30$ seconds for a constant load. The load, in $kW$, is __________.
recategorized
Feb 28, 2017
in
Power Systems
by
piyag476
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1.5k
points)
gate2016ee2
energymeter
revolutions
constantload
0
votes
0
answers
10
GATE2015112
A steady current $I$ is flowing in the $x$ direction through each of two infinitely long wires at $y = ± \frac{L}{2}$ as shown in the figure. The permeability of the medium is $\mu_{0}$. The $\vec{B}$field at $(0,L,0)$ is $\frac{4\mu _{0}I}{3\Pi L} \hat{Z}$ $+\frac{4\mu _{0}I}{3\Pi L} \hat{Z}$ $0$ $\frac{3\mu _{0}I}{4\Pi L} \hat{Z}$
recategorized
Feb 28, 2017
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Power Systems
by
piyag476
(
1.5k
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gate2015ee1
permeability
steadycurrent
0
votes
0
answers
11
GATE2015116
Consider a HVDC link which uses thyristor based linecommutated converters as shown in the figure. For a power flow of $750$ MW from System $1$ to System $2$, the voltages at the two ends, and the current, are given by: $V_{1} = 500 kV, V_{2} = 485 kV$ and $I = 1.5 kA$. If the direction ... $I= −1.5 kA$ $V_{1} = −500 kV, V_{2} = −485 kV$ and $I = −1.5 kA$
recategorized
Feb 28, 2017
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Power Systems
by
piyag476
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1.5k
points)
gate2015ee1
hvdclines
powerflowanalysis
0
votes
0
answers
12
GATE2015117
Base load power plants are P: wind farms. Q: runofriver plants. R: nuclear power plants. S: diesel power plants. P, Q and S only P, R and S only P, Q and R only Q and R only
recategorized
Feb 28, 2017
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Power Systems
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piyag476
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1.5k
points)
gate2015ee1
powerplants
powergeneration
0
votes
0
answers
13
GATE2015122
The self inductance of the primary winding of a single phase, $50$ Hz, transformer is $800$ mH, and that of the secondary winding is $600$ mH. The mutual inductance between these two windings is $480$ mH. The secondary winding of this transformer is short circuited ... neglected. In this condition, what is the effective inductance (in mH) seen by the source? $416$ $440$ $200$ $920$
recategorized
Feb 28, 2017
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Power Systems
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piyag476
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1.5k
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gate2015ee1
selfinductance
sinusoidalvoltagesource
0
votes
0
answers
14
GATE2015123
The primary mmf is least affected by the secondary terminal conditions in a Power transformer. Potential transformer. Current transformer. Distribution transformer.
recategorized
Feb 28, 2017
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Power Systems
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piyag476
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1.5k
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gate2015ee1
primarymmf
turnratio
0
votes
0
answers
15
GATE2015141
Consider the economic dispatch problem for a power plant having two generating units. The fuel costs in Rs/MWh along with the generation limits for the two units are given below: $C_{1}(P_{1})=0.01P^{2}_{1}+30P_{1}+10 ; 100MW \leq P_{1}\leq 150MW$ ... $200$ MW is _______.
recategorized
Feb 28, 2017
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Power Systems
by
piyag476
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1.5k
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gate2015ee1
economicdispatch
incrementalcost
0
votes
0
answers
16
GATE2015142
Determine the correctness or otherwise of the following Assertion $[a]$ and the Reason $[r]$. Assertion: Fast decoupled load flow method gives approximate load flow solution because it uses several assumptions. Reason: Accuracy depends on the power mismatch vector tolerance. Both $[a]$ and $[r]$ ... reason for $[a]$. Both $[a]$ and $[r]$ are false. $[a]$ is false and $[r]$ is true.
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Feb 28, 2017
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Power Systems
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piyag476
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1.5k
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gate2015ee1
powerflows
linelosses
0
votes
0
answers
17
GATE2015143
A $50$ Hz generating unit has Hconstant of $2$ MJ/MVA. The machine is initially operating in steady state at synchronous speed, and producing $1$ pu of real power. The initial value of the rotor angle $\delta$ is 5°, when a bolted three phase to ground short ... input mechanical power to remain at $1$ pu, the value of $\delta$ in degrees, $0.02$ second after the fault is _________.
recategorized
Feb 28, 2017
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Power Systems
by
piyag476
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1.5k
points)
gate2015ee1
shortcircuitfault
synchronousspeed
0
votes
0
answers
18
GATE2015144
A sustained threephase fault occurs in the power system shown in the figure. The current and voltage phasors during the fault (on a common reference), after the natural transients have died down, are also shown. Where is the fault located? Location $P$ Location $Q$ Location $R$ Location $S$
recategorized
Feb 28, 2017
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Power Systems
by
piyag476
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1.5k
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gate2015ee1
singlelinediagram
faultanalysis
0
votes
0
answers
19
GATE2015151
Two singlephase transformers $T_{1}$ and $T_{2}$ each rated at $500$ kVA are operated in parallel. Percentage impedances of $T_{1}$ and $T_{2}$ are $(1 + j6)$ and $(0.8 + j4.8)$, respectively. To share a load of $1000$ kVA at $0.8$ lagging power factor, the contribution of $T_{2}$ (in kVA) is _______.
recategorized
Feb 28, 2017
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Power Systems
by
piyag476
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1.5k
points)
gate2015ee1
laggingpowerfactor
singlephasetransformers
0
votes
0
answers
20
GATE201526
A $3$phase balanced load which has a power factor of $0.707$ is connected to a balanced supply. The power consumed by the load is $5$ kW. The power is measured by the twowattmeter method. The readings of the two wattmeters are $3.94$ kW and $1.06$ kW $2.50$ kW and $2.50$ kW $5.00$ kW and $0.00$ kW $2.96$ kW and $2.04$ kW
recategorized
Feb 28, 2017
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Power Systems
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piyag476
(
1.5k
points)
gate2015ee2
balancedoperation
powermeasurement
0
votes
0
answers
21
GATE2015216
The synchronous generator shown in the figure is supplying active power to an infinite bus via two short, lossless transmission lines, and is initially in steady state. The mechanical power input to the generator and the voltage magnitude $E$ are constant. If one ... transient. Which one of the following waveforms of the rotor angle $\delta$ shows the transient correctly?
recategorized
Feb 28, 2017
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Power Systems
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piyag476
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1.5k
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gate2015ee2
powersystemprotection
sourceofreactivepower
0
votes
0
answers
22
GATE2015217
A 3bus power system network consists of 3 transmission lines. The bus admittance matrix of the uncompensated system is $\begin{bmatrix} j6 &j3 &j4 \\ j3&j7 &j5 \\ j4& j5 & j8 \end{bmatrix}$ pu. If the shunt capacitance of all transmission ... $−j7.0$ $−j8.5$ $−j7.5$ $−j9.0$
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Feb 28, 2017
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Power Systems
by
piyag476
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1.5k
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gate2015ee2
busadmittancematrix
selfadmittance
mutual
admittance
0
votes
0
answers
23
GATE2015220
Find the transformer ratios $a$ and $b$ such that the impedance ($Z_{in}$) is resistive and equals $2.5 \Omega$ when the network is excited with a sine wave voltage of angular frequency of $5000$ rad/s. $a = 0.5, b = 2.0$ $a = 2.0, b = 0.5$ $a = 1.0, b = 1.0$ $a = 4.0, b = 0.5$
recategorized
Feb 28, 2017
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Power Systems
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piyag476
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1.5k
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gate2015ee2
turnratio
transformercore
eddycurrent
0
votes
0
answers
24
GATE2014139
A three phase synchronous generator is to be connected to the infinite bus. The lamps are connected as shown in the figure for the synchronization. The phase sequence of bus voltage is $R$$Y$$B$ ... bus same as infinite bus and its frequency is more than infinite bus same as infinite bus and its frequency is less than infinite bus
edited
Feb 27, 2017
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Power Systems
by
piyag476
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1.5k
points)
gate2014ee1
infinite
bus
synchronization
0
votes
0
answers
25
GATE2014215
A three phase starconnected load is drawing power at a voltage of $0.9$ $pu$ and $0.8$ power factor lagging. The three phase base power and base current are $100$ $MVA$ and $437.384$ $A$ respectively. The linetoline load voltage in $kV$ is ________.
edited
Feb 27, 2017
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Power Systems
by
piyag476
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1.5k
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gate2014ee2
powerfactor
starconnection
0
votes
0
answers
26
GATE2014114
The undesirable property of an electrical insulating material is high dielectric strength High relative permittivity high thermal conductivity High insulation resistivity
retagged
Feb 16, 2017
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Power Systems
by
piyag476
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1.5k
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gate2014ee1
insulation
powersystemanalysis
conductingwires
0
votes
0
answers
27
GATE2014145
The Bode magnitude plot of the transfer function $G(s)=\frac{K(1+0.5s)(1+as)}{s(1+\frac{s}{8})(1+bs)(1+\frac{s}{36})}$ is shown below: Note that $6$ $dB$/$octave$ = $‒20$ $dB$/$decade$. The value of $\frac{a}{bK}$ is ______.
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Feb 16, 2017
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Power Systems
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piyag476
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1.5k
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gate2014ee1
bodeplot
feedbacksystem
0
votes
0
answers
28
GATE2014143
The overcurrent relays for the line protection and loads connected at the buses are shown in the figure The relays are IDMT in nature having the characteristic $t_{op}=\frac{0.12\times TimeMultiplierSetting}{(PlugSettingMultiplier)^{0.02}1}$ The maximum and minimum fault ... for relay $R_B$ to be $0.1$ and $5A$ respectively, the operating time of $R_B$ (in seconds) is ______________
recategorized
Feb 16, 2017
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Power Systems
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piyag476
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1.5k
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gate2014ee1
overcurrent
relays
line
protection
0
votes
0
answers
29
GATE2014142
The fuel cost functions of two power plants are Plant $P_1$ : $C_1=0.05Pg_1^2+APg_1+B$ Plant $P_2$ : $C_2=0.10Pg_2^2+3APg_2+2B$ where, $P_{g1}$ and $P_{g2}$ are the generated powers of two plants, and $A$ and $B$ are the constants. If the two plants optimally share $1000$ ... fuel cost of $100$ $Rs/MWh$, the ratio of load shared by plants $P_1$ and $P_2$ is $1:4$ $2:3$ $3:2$ $4:1$
recategorized
Feb 16, 2017
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Power Systems
by
piyag476
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1.5k
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gate2014ee1
power
plants
powergeneration
0
votes
0
answers
30
GATE2014141
A two bus power system shown in the figure supplies load of $1.0$+$j0.5$ $p.u$. The values of $V_1$ in $p.u$. and $δ_2$ respectively are $0.95$ and $6.00^0$ $1.05$ and $5.44^0$ $1.1$ and $6.00^0$ $1.1$ and $27.12^0$
recategorized
Feb 16, 2017
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Power Systems
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piyag476
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1.5k
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gate2014ee1
powersystemanalysis
reactance
0
votes
0
answers
31
GATE2014140
A distribution feeder of $1$ $km$ length having resistance, but negligible reactance, is fed from both the ends by $400V$, $50$ $Hz$ balanced sources. Both voltage sources $S_1$ and $S_2$ ... $A$ $50$ $A$ and $50$ $A$ $25$ $A$ and $75$ $A$ $0$ $A$ and $100$ $A$
recategorized
Feb 16, 2017
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Power Systems
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piyag476
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1.5k
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gate2014ee1
singlelinediagram
distribution
feeder
0
votes
0
answers
32
GATE2014131
In an unbalanced three phase system, phase current $I_a=1\angle (90^0) pu$ , negative sequence current $I_{b2}=4\angle (150^0) pu$, zero sequence current $I_{c0}=3\angle (90^0) pu$. The magnitude of phase current $I_b$ in $pu$ is $1.00$ $7.81$ $11.53$ $13.00$
recategorized
Feb 16, 2017
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Power Systems
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piyag476
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1.5k
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gate2014ee1
unbalancedsystem
sequencenetworks
0
votes
0
answers
33
GATE2014119
Power consumed by a balanced $3$phase, $3$wire load is measured by the two wattmeter method. The first wattmeter reads twice that of the second. Then the load impedance angle in radians is $\pi /12$ $\pi /8$ $\pi /6$ $\pi /3$
recategorized
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Power Systems
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piyag476
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1.5k
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gate2014ee1
balancedsystem
load
impedance
0
votes
0
answers
34
GATE2014116
A $2$bus system and corresponding zero sequence network are shown in the figure. The transformers $T_1$and $T_2$ are connected as
recategorized
Feb 16, 2017
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Power Systems
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piyag476
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1.5k
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gate2014ee1
sequencenetworks
bussystem
0
votes
0
answers
35
GATE2014115
Threephase to ground fault takes place at locations $F_1$ and $F_2$ in the system shown in the figure If the fault takes place at location $F_1$, then the voltage and the current at bus $A$ are $V_{F1}$ and $I_{F1}$ respectively. If the fault takes place at location $F_2$, then the ... $I_{F1}$ and $V_{F2}$ leads $I_{F2}$ $V_{F1}$ lags $I_{F1}$ and $V_{F2}$ lags $I_{F2}$
recategorized
Feb 16, 2017
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Power Systems
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piyag476
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gate2014ee1
singlelinediagram
powerfactor
0
votes
0
answers
36
GATE2014243
Three phase $100$ $MVA$ ,$25$ $kV$ generator has solidly grounded neutral. The positive, negative, and the zero sequence reactances of the generator are $0.2$ $pu$, $0.2$ $pu$, and $0.05$ $pu$, respectively, at the machine ... bolted single phase to ground fault occurs at the terminal of the unloaded generator, the fault current in amperes immediately after the fault is _________.
recategorized
Feb 15, 2017
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Power Systems
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piyag476
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1.5k
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gate2014ee2
solidlygrounded
zerosequencenetwork
groundfault
0
votes
0
answers
37
GATE2014241
There are two generators in a power system. Noload frequencies of the generators are $51.5$ $Hz$ and $51$ $Hz$, respectively, and both are having droop constant of $1$ $Hz$/$MW$. Total load in the system is $2.5$ $MW$. Assuming that the generators are operating under their respective droop characteristics, the frequency of the power system in $Hz$ in the steady state is ___________.
recategorized
Feb 15, 2017
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Power Systems
by
piyag476
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gate2014ee2
powersystemanalysis
powerproduction
0
votes
0
answers
38
GATE2014240
A synchronous generator is connected to an infinite bus with excitation voltage $E_f$ = $1.3$ $pu$. The generator has a synchronous reactance of $1.1$ $pu$ and is delivering real power $(P)$ of $0.6$ $pu$ to the bus. Assume the infinite bus ... $pu$. Neglect stator resistance. The reactive power $(Q)$ in $pu$ supplied by the generator to the bus under this condition is _________.
recategorized
Feb 15, 2017
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Power Systems
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piyag476
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1.5k
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gate2014ee2
infinitebus
realpower
0
votes
0
answers
39
GATE2014220
While measuring power of a threephase balanced load by the twowattmeter method, the readings are $100$ $W$ and $250$ $W$. The power factor of the load is ______.
recategorized
Feb 15, 2017
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Power Systems
by
piyag476
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1.5k
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gate2014ee2
balancedloads
powerfactor
0
votes
0
answers
40
GATE2014216
Shunt reactors are sometimes used in high voltage transmission systems to limit the short circuit current through the line. compensate for the series reactance of the line under heavily loaded condition. limit overvoltages at the load side under lightly loaded condition. compensate for the voltage drop in the line under heavily loaded condition.
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Power Systems
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piyag476
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gate2014ee2
transmission
system
seriesreactors
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