UNIT-1Bottom of Form1. If A=AT then the matrix is (A)Symmetrical
(B)Skew-symmetric
(C)Hermitian(D)Skew-hermitian
2. If A,BandCare matrices with orders 33, 23 and 42
respectively, how many of the following matrix calculations are
possible?4B,A+B, 3BT+C,AB,BTA, (CB)T,CBA(A)1(B)2
(C)3(D)0
3. IfA=andB=find the matrixXwhich satisfies the matrix
equation
2A+XT= 3B.(A)(B)
(C)(D)
4. The matrixhas determinant, 1 -a+at. Use Cramer's rule to
solve the following system of equation for C.
(A)(B)
(C)(D)
5. One unit of I1 uses 0.2 units of I1 and 0.6 units of I2. One
unit of I2 uses 0.4 units of I1 and 0.2 units of I2. Find the
associated Leontief inverse.(A)(B)
(C)(D)
6. For the commodity marketC=aY+bandI=cr+dFor the money
marketMS=MS*andMD=k1Y+k2r+k3If both markets are in equilibrium,
find the matrixAsuch thatAx=bwherex=andb=(A)(B)
(C)(D)
7. Find the cofactor,A23, of the matrixA=(A)0(B)7
(C)-7(D)23
8. Find the determinant of the matrix
(A)14(B)340
(C)364(D)100
9. Find the value ofaif the following matrix is singular
(A)0(B)3
(C)-3(D)-1/3
10. Which one of the following matrices has an inverse which is
not listed?
A=, B=, C=, D=, E=(A)A(B)B
(C)C(D)D
11. Find AB if (A)(B)
(C)AB is undefined(D)
12. Find A-1, if
13. Determine whether or not the matrices are inverse of each
other.
(A)Yes(B)No
14. Determine whether the matrix is invertible
(A)Yes(B)No
15. Compute the determinant of the matrix by cofactor
expansion
(A)No(B)Yes
(C)(D)
16. If A=-AT then the matrix is (A)Symmetrical
(B)Skew-symmetric(B)
(C)Hermitian(D)Skew-hermitian(D)
17. Compute the determinant of the matrix by cofactor
expansion
(A)1084(B)286
(C)-286(D)146
18. Compute the determinant of the matrix by cofactor
expansion
(A)0(B)-80
(C)80(D)-40
19. Compute the determinant of the matrix by cofactor
expansion.
(A)-9(B)-36
(C)0(D)36
20. Compute the determinant of the matrix by cofactor
expansion
(A)-200(B)100
(C)-100(D)-50
21. If A= (A*)T then the matrix is (A)Symmetrical
(B)Skew-symmetric(B)
(C)Hermitian(D)Skew-hermitian(D)
22. If A= -(A*)T then the matrix is (A)Symmetrical
(B)Skew-symmetric(B)
(C)Hermitian(D)Skew-hermitian(D)
23. Which one of the following matrices reveals the topology of
the power system network?(A)Bus incidence matrix(B)Primitive
impedance matrix
(C)Primitive admittance matrix(D)Bus impedance matrix
24. The equivalent Thevenins bus admittance matrix of a two-bus
system with identical generators on both buses is The generator
reactance and interconnected line reactance will be
respectively(A)j0.05 & j0.1(B)-j0.05 & j0.1
(C)-j0.05 & -j0.1(D)j0.1 & j0.05
UNIT-2
1. The bus admittance matrix of the network shown in the given
figure, for which the marked parameters are pu impedances, is
(A)(B)
(C)(D)
2. A power system network consists of three elements 0-1, 1-2,
2-0 of pu impedances 0.2, 0.4 and 0.4 respectively. Its bus
impedance matrix is given by(A)(B)
(C)(D)
3. Zbus for the following system is
(A)(B)
(C)(D)None of these
4. Ybus for the following system is:-(impedance is given)
(A)(B)
(C)(D)None of these
5. Zbus for the following system is
(A)(B)
(C)(D)None of these
6. Zbus for the following system is
(A)(B)
(C)(D)
7. Determine Zbus for the following system is
(A)Zbus=[j0.05](B)
(C)(D)Any of the above
8. Ybus for the following system is
(A)(B)
(C)(D)Any of the above
9. Ybus for the following system is Bottom of Form
(A)(B)
(C)(D)None of these
10. Ybus for the following system isBottom of Form
(A)(B) Bottom of Form
(C)(D)
11. Zbus for the following system is
(A)(B)
(C)(D)
12. Zbus for the following system is
(A)(B)
(C)(D)
13. Find Ybus for the following system is
(A)(B)
(C)(D)
14. Find Zbus for the following system is
(A)(B)
(C)(D)
15. Find Ybus for the following system is
(A)(B)
(C)(D)
16. Find Zbus for the following system is
(A)(B)
(C)(D)
17. Find Ybus for the following system is
(A)(B)
(C)(D)
18. Normally ZBUS matrix is a (A)Null matrix(B)Sparse matrix
(C)Full matrix(D)Unity matrix
19. If and I=AIs where I is equal to phase current vector, and
IS is equal to symmetrical current vector, then which one of the
following matrices is the symmetrical components transformation
matrix A?
(A)
(B)
(C)
(D)
20. is the pe unit impedance on the power base and voltage base
. What would be the per unit impedance on the new power base
?(A)
(B)
(C)
(D)
UNIT-3
1. For measuring positive, negative and zero sequence voltages
in a system, the reference is taken as:(A)Neutral of the system
only(B)Ground only
(C)For zero sequence neutral and for positive and negative the
ground(D)None of the above
2. A shunt fault is characterized by:(A)Increase in current,
frequency and p.f.(B)Increase in current, reduction in frequency
and p.f.
(C)Increase in current, frequency and reduction in p.f.(D)None
of the above
3. if Ia1 is the positive sequence current of an alternator and
Z1, Z2 and Z0 are the sequence impedances of the alternator. The
drop produced by the current Ia1 will be:(A)Ia1Z1(B)Ia1(Z1+Z2)
(C)Ia1(Z1+Z2+Z0)(D)Ia1(Z2+Z0)
4. For the system shown in diagram below, a LG fault on the line
side of the transformer is equivalent to
(A)A LG fault on the generator side of the transformer(B)A LL
fault on the generator side of the transformer
(C)A LLG fault on the generator side of the transformer (D)A LLL
fault on the generator side of the transformer
5. Zero sequence currents can flow from a line into a
transformer bank if the windings are in(A)Grounded
star/delta(B)Delta/star
(C)Star/star grounded(D)Delta/delta
6. Consider the following statement regarding the fault
analysis:i) The neutral grounding impedance Zn appears an 3Zn in
zero sequence equivalent circuits.ii) For faults on transmission
lines, 3-phase fault is the least severe amongst other faults.iii)
The positive and negative sequence networks are not affected by
method of neutral grounding.Which of the statements given above are
correct?(A)2 and 3(B)2 and 1
(C)1 and 3(D)1, 2 and 3
7. If a sudden short circuit occurs on a power system
(considered as R-L series circuit), the current wave-form consists
ofi) A decaying a.c. currentii) A decaying d.c. current.Let the
alternator reactance be X and the power system resistance R. which
one of the following is correct?
(A)The decay in (1) is caused by the increase in X but in (2) is
caused by R(B)The decay in (1) is caused by the increase in R but
in (2) is caused by X
(C)The decay in both (1) and (2) is caused by R(D)The decay in
both (1) and (2) is caused by increase in X
8. Steady state operating condition of a power system
indicates(A)A situation when the connected load is absolutely
constant(B)A situation when the generated power is absolutely
constant
(C)A situation when both connected load and generated power are
equal to each other and remain constant.(D)An equilibrium state
around which small fluctuations in power, both in generation and
load, occur all the time
9. In a power system, the 3-phase fault MVA is always higher
than the single-line-ground fault MVA at bus(A)True(B)False
(C)Cant be determined(D)
10. For a fault at the terminal of a synchronous generator, the
fault current is maximum for a Bottom of Form11. (A)3-phase
fault(B)3-phase to ground fault
(C)Line-to-ground fault(D)Line-to-line fault
11. For an unbalanced fault, with paths for zero sequence
currents, at the fault point(A)The negative and zero sequence
voltages are minimum(B)The negative and zero sequence voltages are
maximum
(C)The negative sequence voltage is minimum and zero sequence
voltages are maximum(D)The negative sequence voltage is maximum and
zero sequence voltages are minimum
12. The sequence components of the fault current are as follows:
Ipositive=j1.5pu, Inegative= -j0.5pu, Izero= -j1.0pu. the type of
fault in the system is(A)LG(B)LL
(C)LLG(D)LLLG
13. for a three phase to ground fault is(A)(B)
(C)(D)Not defined
14. for a three phase to ground fault is(A)(B)Where
(C)(D)
15. for a three phase to ground fault is(A)(B)
(C)(D)Not defined
16. for a three phase to ground fault is(A)(B)
(C)(D)
17. for a three phase fault is(A)(B)
(C)(D)Not defined
18. for a three phase fault is(A)(B)Where
(C)(D)
19. for a three phase fault is(A)(B)
(C)(D)Not defined
20. for a three phase fault is(A)(B)
(C)(D)
21. for a double phase to ground fault is(A)(B)
(C)(D)Not defined
22. for a double phase to ground fault is(A)(B)Where
(C)(D)
23. for a double phase to ground fault is(A)(B)
(C)(D)Not defined
24. for a double phase to ground fault is(A)(B)
(C)(D)
25. for a single phase to ground fault is(A)(B)
(C)(D)Not defined
26. for a single phase to ground fault is(A)(B)Where
(C)(D)
27. for a single phase to ground fault is(A)(B)
(C)(D)Not defined
28. for a single phase to ground fault is(A)(B)
(C)(D)
29. for a double phase fault is(A)(B)
(C)(D)Not defined
30. for a double phase fault is(A)(B)Where
(C)(D)
31. for a double phase fault is(A)(B)
(C)(D)Not defined
32. for a double phase fault is(A)(B)
(C)(D)
UNIT-4
1. In load flow studies of a power system, the quantities
specified at a voltage controlled bus are _____ and
______.(A)(B)
(C)V, I(D)
2. In load flow analysis, the load connected at a bus is
represented as(A)Constant current drawn from the bus(B)Constant
impedance connected at the bus
(C)Voltage and frequency dependent source at the bus(D)Constant
real and reactive power drawn from the bus
3. In load flow analysis, a voltage controlled bus is treated as
in subsequent iteration for a reactive power limit is violated
(A)True(B)False
(C)Cant be determined(D)
4. If reference bus is changed in two load flow runs with same
system data and power obtained for reference bus taken as specified
P & Q in the later run(A)The system losses will be unchanged
but complex bus voltage will change(B)The system losses will change
but complex bus voltage remains unchanged
(C)The system losses as well as complex bus voltage will
change(D)The system losses as well as complex bus voltage will be
unchange
5. The per unit voltage of two synchronous machines connected
through a lossless line are 0.95 and 1.0. Match the two sides of
the following(a)Real power of machine 1(p)Positive real power
(b)Reactive power of machine 1(q)Positive reactive power
(c)Power factor of machine(r)Negative real power
(s)Negative reactive power
(t)Leading power factor
(u)Lagging power factor
(A)a-p, b-s, c-u(B)a-p, b-r, c-u
(C)a-q, b-r, c-t(D)a-p, b-s, c-t
6. Two transposed 3- lines run parallel to each other. The
equation describing the voltage drop in both lines given below
Compute the self and mutual zero sequence impedances of this
system i.e. complete Z011, Z012, Z021, Z022 in the following
equation V01=Z011I01+ Z012I02V02=Z021I01+ Z022I02Where V01, V02,
I01, I02 are the zero sequence voltage drops and currents for the
two lines repectively.(A)Z011= Z022=j0.59, Z012=Z021 =j0.44(B)Z011=
Z022=j0.37, Z012=Z021 =j0.22
(C)Z011= Z022=j0.25, Z012=Z021 =j0.10(D)Z011= Z022=j0.59,
Z012=Z021 =j0.22
7. A power system consists of 2 areas connected by a single tie
line. It is required to carry out a load flow study on this system.
While entering the network data, the tie line data is inadvertently
left out. If the load flow program is run with this incomplete
data.(A)The load flow will converge only if the slack bus is
specified in area 1(B)The load flow will converge only if the slack
bus is specified in area 1
(C)The load flow will converge only if the slack bus is
specified in either area 1 or area 2(D)The load flow will not
converge only if only one slack bus is specified
8. A power system consist of 300 buses out of which 20 buses are
generator bus, 25 buses are one with reactive power support and 15
buses are the one with fixed shunt capacitors. All the other buses
are load buses. It is proposed to perform a load flow analysis in
the system using N-R jacobian matrix is(A)553 X 553(B)540 X 540
(C)555 X 555(D)554 X 554
9. The positive, negative and zero sequence impedances of a
solidly grounded system under steady state condition always follow
the relations:
(A)Z1>Z2>Z0 (B)Z1Z2(D)None of the above
10. Buses for load flow studies are classified as (i) the load
bus, (ii) the generator bus and (iii) the slack busThe correct
combination of the pair of quantities specified having their usual
meaning for different buses is
11. in the solution of load flow equation, NR method is superior
to the GS method, because the (A)Time taken to perform one
iteration in the NR method is less when compared to the time taken
in the GS method(B)Number of iteration required in the NR method is
less when compared to that in the GS method
(C)Number of iteration required is not independent of the size
of the system in the NR method(D)Convergence characteristic of the
NR method are not affected by the selection of slack bus
12. Consider the following quantities:1Real power2Reactive
power
3Power factor4Input current
5Bus voltage magnitude6Bus voltage phase angle
For the purpose of the load flow studies of a power system, each
bus or node is associated with which one of the combination of
above four quantities(A)1,3,4 & 5(B)1,2,3 &4
(C)2,3,5,& 6(D)1,2,5 & 6
13. At slack bus, which one of the following combinations of
variables is specified?(A)(B)P,Q
(C)(D)
14. A voltage controlled bus is characterized by the
specified(A)Real and reactive powers(B)Real powers and voltage
phase angle
(C)Real power and voltage magnitude(D)Reactive power and voltage
magnitude
15. Consider the following statement:Transient stability of a
synchronous generator feeding power to an infinite bus through a
transmission line can be increased byi) Increasing the steam supply
to the turbine driving the generator during fault clearing.ii)
Connecting resistors at the generator terminals during fault
condition.iii) Employing a faster excitation system.iv) Quickly
throwing off the generator load.Which of these statements are
correct?(A)2 and 3(B)3 and 4
(C)1 and 2(D)2 and 4
16. In Gauss-Siedel method of power flow problem, the number of
iterations may be reduced if the correction in voltage at each bus
is multiplied by
(A)Gauss constant(B)Acceleration constant
(C)Deceleration constant(D)Blocking factor
17. Match list-1 (Bus types) with list-2 (Pairs of variables)
and select the correct answer using the codes given below the
lists:List-I(Bus types)List-II(Pairs of variables)
A. Load Bus1. P & V
B. Generator Bus2. P & Q
C. Slack Bus3. V &
Codes: A B C A B C
(A) 1 2 3(B) 2 3 1
(C) 1 3 2(D) 2 1 3
18. In load flow studies of a power system, the voltage control
bus is specified by(A)Real and reactive power(B)Real power and
voltage magnitude
(C)Voltage and voltage phase angle(D)Reactive power &
voltage magnitude
19. The power angle characteristics of machine-infinite bus
system is
It is operating at =30. Which one of the following is the
synchronizing coefficient at the operating point?(A)1.0(B)
(C)2.0(D)
20. Possible faults that may occur on a transmission line
are1.3-phase fault2.Double line to ground fault
3.Double line fault4.Line to ground fault
(A)1-2-3-4(B)1-4-3-2
(C)1-3-2-4(D)1-3-4-2
21. Consider the following statements:i) It is easier to
construct the YBUS matrix as compared to ZBUS.ii) ZBUS is a full
matrix while YBUS is sparse.iii) YBUS can be easily modified
whenever the network changes as compared to the ZBUS.Which of these
statements are correct?(A)1 and 2(B)2 and 3
(C)1 and 3(D)1, 2 and 3
22. The bus impedance matrix of a 4-bus power system is given
by
A branch having an impedance of j0.2 is connected between bus 2
and the reference. Then the values of Z22, new and Z23,new of the
bus impedance matrix of the modified network are
respectively(A)j0.5408 and j0.4586(B)j0.1260 and j0.0956
(C)j0.5408 and j0.0956(D)j0.1260 and j0.1630
23. The network shown in the given figure has impedances in pu
as indicated. The diagonal element Y22 of the bus admittance matrix
YBUS of the network ise(A)-j19.8(B)j20.0
(C)+j0.2(D)-j19.95
24. The Gauss Siedel load flow method has following
disadvantages. Tick the incorrect statement.(A)Unreliable
convergence(B)Slow convergence
(C)Choice of slack bus affects convergence(D)A good initial
guess for voltages is essential for convergence
25. For a power system the admittance and impedance matrices for
the fault studies are as follows.
The pre-fault voltages are 1.0pu at all the buses. The system
was unloaded prior to the fault. A solid 3-phase fault takes place
at bus 2.The post fault voltages at buses 1 & 3 in pu
are(A)0.24, 0.63(B)0.31, 0.76
(C)0.33, 0.67(D)0.67, 0.33
26. For a power system the admittance and impedance matrices for
the fault studies are as follows.
The pre-fault voltages are 1.0pu at all the buses. The system
was unloaded prior to the fault. A solid 3-phase fault takes place
at bus 2.The per unit faults feed from generators connected to
buses 1 and 2 respectively are(A)1.20, 2.51(B)1.55, 2.61
(C)1.66, 2.50(D)5.00, 2.50
27. Consider the two power systems shown in figure A below,
which are operating in steady state at the same frequency. Separate
load flow solutions are computed individually for the two systems,
corresponding to this scenario. The bus voltage phasors so obtained
are indicated on figure AThese two isolated systems are now
interconnected by a short transmission line shown in figure B, and
it is found that P1=P2=Q1=Q2=0
(A)10(B)25
(C)-30(D)30
28. For the Ybus matrix of a 4-bus system given in p.u., the
buses having shunt elements are
(A)3 and 4(B)2 and 3
(C)1 and 2(D)1, 2 and 4
29. Consider two buses connected by an impedance of (0+j5). The
bus 1 voltage is 10030, and bus 2 is 1000V. the real and reactive
power supplied by bus 1, respectively are(A)1000W, 268VAR(B)-1000W,
-134VAR
(C)276.9W, -56.7VAR(D)-276.9W, 56.7VAR
30. A three bus network is shown in the figure below indicating
the p.u. impedance of each element.
The bus admittance matrix, Ybus, of the network is(A)(B)
(C)(D)
31. The bus admittance matrix of a three-bus three line system
is
If each transmission line between the two buses is represented
by an equivalent -network, the magnitude of the shunt susceptance
of the line connecting bus 1 and 2 is(A)4(B)2
(C)1(D)0
32. A single phase load is supplied by a single pase voltage
source. If the current flowing from load to the source is 10-150A
and if the voltage at the load terminals is 10060V, then
the(A)Loads absorbs real power and delivers reactive power(B)Loads
absorbs real power and absorbs reactive power
(C)Loads delivers real power and delivers reactive power(D)Loads
delivers real power and absorbs reactive power
33. For aa power system network with n nodes, Z33 of its bus
impedance matrix is j0.5pu. the voltage at node 3 is 1.3-10pu. If a
capacitor having reactance of j3.5pu is now added to the network
between node 3 and the reference node, the current drawn by the
capacitor pu is(A)0.325-100(B)0.325800
(C)0.371-100(D)0.43380
34. In the following network, the voltage magnitudes at all
buses are equal to 1 pu, the voltage phase angles are very small,
and the line resistances are negligible. All the line reactances
are equal to j1.
The voltage phase angles in rad at buses 2 and 3 are(A)2= -0.1,
3= -0.2(B)2= 0, 3= -0.1
(C)2= 0.1, 3= 0.1(D)2= 0.1, 3= 0.2
35. In the following network, the voltage magnitudes at all
buses are equal to 1 pu, the voltage phase angles are very small,
and the line resistances are negligible. All the line reactances
are equal to j1.
If the base impedance and the line to line base voltage are 100
and 100kV, respectively, then the real power in MW delivered by the
generator connected at the slack bus is(A)-10(B)0
(C)10(D)20