MCQ On

Unit No. 01
Basics of Network
Prepared By,
Prof. Chaitanya Deshpande
Prof. Snehal Dharme
Department of Electrical Engineering
Zeal College of Engineering and Research, Pune
S.E. Electrical (Network Analysis) Department of Electrical Engineering, ZES, ZCOER
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MCQ’s on Source transformation

1. By using source transformation voltage source in series resistor is replaced by

(a) Voltage source in series with a (b) Current source in parallel with a
resistor resistor
(c) Voltage source in parallel with a (d) Current source in series with a resistor
resistor

Ans: (b): In Source transformation, a voltage source in series with a resistor is replaced
by a current source in parallel with the same resistor and vice versa.

2. Source Transformation is _____________

(a) Unilateral (b) Unique

(c) Bilateral (d) Complicated

Ans: (b): In Source transformation, a voltage source in series with a resistor is replaced
by a current source in parallel with the same resistor and vice versa. So, it is
bilateral.

3. If there are two resistors in parallel and in series with a voltage source then
___________

(a) Parallel resistor has no effect (b) Series resistor has no effect
(c) Both has their respective effects (d) Both has no effect on the voltage source

Ans: (a): In source transformation, the voltage source in series with a resistor to be
replaced by a current source in parallel with the same resistor and vice versa. So
other resistors are redundant and have no effect.

4. Using source transformation, calculate the voltage.

(a) 4.33 V (b) 39 V

(c) 0.230 V (d) 36 V

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S.E. Electrical (Network Analysis) Department of Electrical Engineering, ZES, ZCOER
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5. Which element(s) has no effect in the given circuit?

(a) 7Ω (b) 10Ω

(c) Both 7Ω and 10Ω (d) Voltage Source

Ans: Explanation: Voltage in series with a resistor in replaced by a current source but
here 10Ω is in parallel. So, it is redundant and has no effect.

6. The value of current source is __________ after replacing the given network with a
single current source and a resistor.

(a) 70 V (b) 60V

(c) 90 V (d) 80 V

Ans: Explanation: In the given circuit 9Ω resistor has no effect. 10*6=60V, 60V+20V=80V.

7. If there is a 12A current source in series with 2Ω and in parallel with a 4Ω resistor,
then voltage V=?

(a) 24 V (b) 48 V
(c) 3 V (d) 6 V

Ans: Explanation: 2Ω resistor is redundant. 12*4=48V.

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S.E. Electrical (Network Analysis) Department of Electrical Engineering, ZES, ZCOER
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8. Find the current flowing through 4Ω resistor shown in network below.

(a) 1.33 A (b) 2.35 A

(c) 1.66 A (d) 2.66 A

Ans: Explanation: By using source transformation the above network is reduced and
then by current division rule I4Ω= 5*(2/2+4) =1.66A.

9. Calculate the power delivered by the 50V source.

(a) 274 W (b) 276 W

(c) 285 W (d) 291 W

Ans: Explanation: By using source transformation the above network is reduced and
current in the circuit is found out and later power delivered by 50V source=
50*current in the circuit= 50*5.48A= 274W.

10. Source transformation technique is mainly based on __________ law.

(a) Newton’s law (b) Kirchhoff’s law

(c) Ohms law (d) Einstein’s law

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11. Using source transformation, calculate Vm.

(a) 2 V (b) -2 V
(c) 1 V (d) -1 V

12. In source transformation,

(a) Voltage source remains same (b) Current sources remain same
(c) Both voltage and current sources (d)Resistances/Impedances
undergo change remain same

13. If there are five 20V voltage sources in parallel, then in source transformation
__________

(a) All are considered (b) Only one is considered

(c) All are ignored (d) Only two are considered

Ans: Explanation: In parallel connection, voltage remains same, hence option (b)

14. Calculate the total current in the circuit.

(a) 2.3 mA (b) 4.3 mA

(c) 3.3 mA (d) 1.3 mA

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S.E. Electrical (Network Analysis) Department of Electrical Engineering, ZES, ZCOER
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15. Find the value of voltage once source transformation is applied to the circuit.

(a) 10 V (b) 30 V
(c) 50 V (d) 70 V

MCQ’s on Mesh analysis, Node analysis, KCL and KVL

16. If there are M branch currents, then we can write ___________ number of
independent equations.

(a) M-2 (b) M-1

(c) M (d) M+1

Ans: If there are M branch currents, then we can write M number of independent
equations. Number of independent equations = M.

17. If there are M meshes, B branches and N nodes including reference node, the
number of mesh currents is given as M=?

(a) B + (N+1) (b) B + (N-1)

(c) B-(N+1) (d) B-(N-1)

Ans: Explanation: If there are M meshes, B branches and N nodes including reference
node, the number of mesh currents is given as M= B-(N-1).

18. Mesh analysis employs the method of ___________

(a) KVL (b) KCL

(c) Both KVL and KCL (d) Neither KVL nor KCL

Ans: KVL employs mesh analysis to find the different mesh currents by finding the IR
products in each mesh.

19. Mesh analysis is generally used to determine _________

(a) Voltage (b) Current

(c) Resistance (d) Power

Ans: Mesh analysis uses Kirchhoff’s Voltage Law to find all the mesh currents. Hence it
is a method used to determine current.

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S.E. Electrical (Network Analysis) Department of Electrical Engineering, ZES, ZCOER
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20. Mesh analysis can be used for __________

(a) Planar circuits (b) Non-planar circuits

(c) Both planar and non-planar (d) Neither planar nor non-planar circuits
circuits

Ans: If the circuit is not planar, the meshes are not clearly defined. In planar circuits, it
is easy to draw the meshes hence the meshes are clearly defined.

21. Mesh analysis is applicable for non-planar networks also.

(a) True (b) False

Ans: Mesh analysis is applicable only for planar networks. A circuit is said to be planar
if it can be drawn on a plane surface without crossovers.

22. A mesh is a loop which contains ____ number of loops within it.

(a) 1 (b) 2
(c) 3 (d) No loop

Ans: A loop is a closed path. A mesh is defined as a loop which does not contain any other
loops within it.

23. Consider the circuit shown below. The number mesh equations that can be formed
are?

(a) 1 (b) 2
(c) 3 (d) 4

24. If there are 5 branches and 4 nodes in graph, then the number of mesh equations
that can be formed are?

(a) 2 (b) 4
(c) 6 (d) 8

Ans: Number of mesh equations= B-(N-1). Given number of branches = 5 and number of
nodes = 4. So Number of mesh equations = 5-(4-1) =2.

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S.E. Electrical (Network Analysis) Department of Electrical Engineering, ZES, ZCOER
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25. Find the value of the currents I1 and I2 flowing clockwise in the first and second
mesh respectively.

(a) 5A, 0A (b) -5A, 0A

(c) 0A, 5A (d) 0A, -5A

26. Find the value of V if the current in the 3 ohm resistor = 0.

(a) 3.5 V (b) 6.5 V

(c) 7.5 V (d) 8.5 V

27. Find the value of V1 if the current through the 1 ohm resistor = 0

(a) 83.33V (b) 78.89V

(c) 87.87V (d) 33.33V

28. Calculate the current I3 in the following circuit.

(a) -8 A (b) -2 A
(c) 2 A (d) 8 A

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S.E. Electrical (Network Analysis) Department of Electrical Engineering, ZES, ZCOER
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29. Mesh current method also known as

(a) Closed loop current (b) Loop current method

(c) Branch current method (d) Open current method

30. In any linear network, the elements like inductor, resistor and capacitor
always_________

(a) Exhibit changes due to change in (b) Exhibit changes due to change in
temperature voltage
(c) Exhibit changes due to change in (d) Remains constant irrespective of
time change in temperature, voltage and
time

31. If innumerable branches are present in parallel configuration in a network, which

method approves to be extensively beneficial for network analysis?

(a) Node method (b) Mesh method

(c) Both (a) and (b) (d) None of the above

32. Under which conditions does the source transformation technique remain directly
inapplicable?

(a) Only in the absence of impedance (b) Only in the absence of impedance in
in series with a voltage source parallel with a current source
(c) Both a and b (d) None of the above

33. What will be the value of equivalent single source, if the two voltage sources
connected in series combination possess equal or similar polarity?

(a) Addition of two sources with (b) Addition of two sources with opposite
polarities similar to that of two polarity
sources
(c) Difference between the two (d) Difference between the two sources
sources with polarities similar to that with polarities similar to that of greater
of two sources among the two sources

34. How is the loop analysis different in application/functioning level as compared to

Kirchoff's law?

(a) Utilization of loop currents (b) Capability of branch current to carry

instead of branch currents for writing multiple networks
equations
(c) Reduction in the number of (d) All of the above
unknowns for complex networks

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S.E. Electrical (Network Analysis) Department of Electrical Engineering, ZES, ZCOER
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35. Which law plays a significant role in the loop analysis of the network?

(a) Utilization of loop currents (b) Capability of branch current to carry

instead of branch currents for writing multiple networks
equations
(c) Reduction in the number of (d) All of the above
unknowns for complex networks

36. KCL is based on the fact that

(a) There is a possibility for a node to (b) There cannot be an accumulation of

store energy. charge at a node.
(c) Charge accumulation is possible at (d) Charge accumulation may or may not
node be possible.

Ans: Since the node is not a circuit element, any charge which enters node must leave
immediately.
37. The algebraic sum of voltages around any closed path in a network is equal to
____________

(a) Infinity (b) 1

(c) 0 (d) Negative polarity

38. Calculate potential difference between x and y

(a) 4.275 V (b) -4.275 V

(c) 4.527 V (d) -4.527 V

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S.E. Electrical (Network Analysis) Department of Electrical Engineering, ZES, ZCOER
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39. Find R from following circuit

(a) 17.5 ohm (b) 17.2 ohm

(c) 17.4 ohm (d) 17.8 ohm

40. Determine currents I1 , I2 and I3.

(a) -3.3A, -8.5A, 2.4A (b) 3A, -8A, 2A

(c) 3.3A, 8.5A, -2.4A (d) 3.2A, 8.6A, 2.3A

Ans: I1 = I1 – I2 + 8 + I3 + 3
I2 – I3 = 11 -> 1
And -11 I1 – 7(I1 – I2) = 0
-18 I1 + 7 I2 = 0 -> 2
And -11 I1 – 15 I3 =0 -> 3
Solving I1 = 3.32A I2 = 8.5A I3 = -2.4A.

41. All _____________ are loops but _______________ are not meshes

(a) Loops, Meshes (b) Meshes, loops

(c) Branches, loops (d) Nodes, Branches

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S.E. Electrical (Network Analysis) Department of Electrical Engineering, ZES, ZCOER
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42. Solve for I

(a) -0.5 A (b) 0.5 A

(c) -0.2 A (d) 0.2 A

43. A junction where two (or) more than two network elements meet is known as a
______________

(a) Node (b) Branch (c) Loop (d) Mesh

44. Mesh analysis is generally used to determine?

(a) Voltage (b) Current

(c) Resistance (d) Power

45. KVL is associated with____________

(a) Mesh analysis (b) Nodal analysis

(c) Both mesh and nodal analysis (d) Neither mesh nor nodal

46. KCL is associated with_________

(a) Mesh analysis (b) Nodal analysis

(c) Both mesh and nodal analysis (d) Neither mesh nor nodal

47. Nodal analysis is generally used to determine?

(a) Voltage (b) Current

(c) Resistance (d) Power

48. Find the value of the source current from the following circuit.

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S.E. Electrical (Network Analysis) Department of Electrical Engineering, ZES, ZCOER
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(a) 2.54 A (b) 6.67 A

(c) 3.35 A (d) 7.65 A
Ans: I3 =(3+j0)A
V2 =I3R=(3+j0)(8+j0)=(24+j0)V
I2=V2/Xc=(j1.5) A
I1 =I2 +I3 =(0+j1.5)+(3+j0)=(3+j1.5)A
I1=(32+1.52)1/2= 3.35A.
49. Find the value of the source voltage from the following circuit.

(a) 49.2 V (b) 34.6 V

(c) 65.2 V (d) 25.6 V

Ans: I3 =(3+j0)A
V2 =I3R=(3+j0)(8+j0)=(24+j0)V
I2=V2/Xc=(0 + j1.5) A
I1 =I2 +I3 =(0+j1.5)+(3+j0)=(3+j1.5)A
I1=(32+1.52)1/2= 3.35A.
V1 =I1(R+jXL) =(15+j30)V
E=V1 +V2 =(39+j30)V

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S.E. Electrical (Network Analysis) Department of Electrical Engineering, ZES, ZCOER
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E=(392+302)1/2= 49.2V

50. Kirchhoff’s laws are valid for ___________

(a) Linear circuits only (b) Both linear and nonlinear circuits
(c) Neither linear nor nonlinear (d) Can’t say
circuits

51. KCL is based on _____________

(a) Law of conservation of energy (b) Law of conservation of charge

(c) Both conservation of energy and (d) Neither conservation of energy nor
charge charge

52. KVL is based on___________

(a) Law of conservation of energy (b) Law of conservation of charge

(c) Both conservation of energy and (d) Neither conservation of energy nor
charge charge

53. Consider the circuit shown below. Find the current I1 (A).

(a) 1 (b) 1.33 (c) 1.66 (d) 2

54. Find the current I2 (A) in the circuit shown in the question 1 from above circuit.

(a) 1.33 (b) 2.33 (c) 3.33 (d) 4.33

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S.E. Electrical (Network Analysis) Department of Electrical Engineering, ZES, ZCOER
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55. Consider the circuit shown in the figure. Find the current I1 (A)

(a) -1 (b) -2 (c) -3 (d) -4

56. Find the current I2 (A) in the figure shown above

(a) -2 (b) -1 (c) 2 (d) 1

57. Find the current i1 in the circuit shown below.

(a) 8 (b) 9 (c) 10 (d) 11

58. Find the current i2 in the circuit shown above.

(a) 6.27 (b) 7.27 (c) 8.27 (d) 9.27

59. Which method is best for voltage sources?

(a) Mesh (b) Nodal (c) Superposition (d) Differentiation

analysis analysis method method

60. When there is a current source between two loops which method is preferred?

(a) Mesh voltage (b) Nodal current (c) Supermesh (d) Supernode
analysis analysis

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S.E. Electrical (Network Analysis) Department of Electrical Engineering, ZES, ZCOER
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61. Determine the current through 5Ω resistor in the network given below.

(a) 3.38 A (b) 6.01 A (c) 3.27 A (d) 1.27 A

62. Find the power supplied by the dependent voltage source in the circuit given
below.

(a) 400 W (b) 383 W (c) 412 W (d) 148 W

63. If there are b branches and n nodes, then how many node-voltage equations are
required?

(a) n (b) b+1 (c) n-1 (d) b

Ans: If there are n nodes then n-1 nodal equations are required to describe the circuit.
Branches do nothing in this case.

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S.E. Electrical (Network Analysis) Department of Electrical Engineering, ZES, ZCOER
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64. Determine V1 of the given network.

(a) -0.17 V (b) 4.83 V (c) 5 V (d) 2.62 V

Ans: Super node: V3-V2=5. Applying KCL at node1 and at super node gives the equations
which on solving, required voltages are obtained.

65. Consider the figure shown below. Find the voltage (V) at node 1.

(a) 13 (b) 14 (c) 15 (d) 16

66. Use above figure and find the voltage (V) at node 2.

(a) 3 (b) 4 (c) 5 (d) 6

67. Use above fig. and find the voltage (V) at node 3.

(a) 4.5 (b) 5.5 (c) 6.5 (d) 7.5

MCQs on Network Graph theory

68. The number of branches incident at the node of a graph is called?

(a) Degree of the node (b) order of the node

(c) Status of node (d) Number of nodes

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69. If no two branches of the graph cross each other, then the graph is called?

(a) Directed graph (b) Undirected graph

(c) Planner graph (d) Non-planner graph

Ans: If a graph can be drawn on a plane surface such that no two branches of the graph
cross each other, then the graph is called planar graph .

70. Number of twigs in a tree are? n- number of nodes

(a) n (b) n+1 (c) n-1 (d) n-2

Ans: Twig is a branch in a tree. Number of twigs in a tree are n-1. If there are 4 nodes in
a tree then number of possible twigs are 3.

71. If A represents incidence matrix, I represent branch current vectors, then?

(a) AI = 1 (b) AI = 0 (c) AI=2 (b) AI = 3

Ans: If A represents incidence matrix, I represents branch current vectors, then the
relation is AI= 0 that is its characteristic equation must be equated to zero

72. The current in a closed path in a loop is called?

(a) Loop current (b) Branch current (c) Link current (d) Twig current

73. Tie-set is also called?

(a) f loop (b) g loop (c) d loop (d) e loop

74. Consider the graph shown below. If a tree of the graph has branches 4, 5, 6, then
one of the twigs will be?

(a) 1 (b) 2 (c) 3 (d) 4

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Ans: Branches of the tree are called twigs. So 4, 5, 6 are the twigs of the tree. The current
in any branch of a graph can be found by using link currents.

75. Consider the graph shown in the above question. If a tree of the graph has branches
4, 5, 6, then one of the links will be?

(a) 3 (b) 4 (c) 5 (d) 6

Ans: The branches of the co-tree are called links. So the links will be 1, 2, 3. For a given
tree of a graph addition of each link between any two nodes form a loop called
fundamental loop

76. The loop current direction of the basic loop formed from the tree of the graph is?

(a) Same as the direction of branch (b) Opposite to the direction of link
current current
(c) Same as the direction of link (d) Opposite to the direction of branch
current current

77. For Tie-set matrix, if the direction of current is same as loop current, then we place
___ in the matrix.

(a) +1 (b) -1 (c) 0 (d) +1 and -1

78. The matrix formed by link branches of a tie set matrix is?

(a) Row matrix (b) Column matrix (c) Diagonal matrix (d) Identity
matrix
79. The number of tie set matrices formed from a graph are?

(a) NN-1 (b) NN (c) NN-2 (d) NN+1

80. Consider the graph shown below. The direction of the cut-set of node ‘a’ is?

(a) Right (b) Left (c) Upwards (d) Downwards

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Ans: The direction of the cut set at node ‘a’ will be the direction of the branch current at
node ‘a’. So the direction of the current will be upwards.

81. Consider the graph shown above in question. The direction of the cut-set at node
‘b’ will be?

(a) Right (b) Left (c) Upwards (d) Downwards

82. In the graph shown above in the question 80, the direction of the cut-set at node ‘c’
is?

(a) Right (b) Left (c) Upwards (d) Downwards

83. In the graph shown in the question 80, the direction of the cut-set at node ‘d’ will
be?

(a) Right (b) Left (c) Upwards (d) Downwards

84. A graph is said to be a directed graph if ________ of the graph has direction.

(a) 1 branch (b) 2 branches (c) 3 branches (d) every branch

85. If a graph consists of 5 nodes, then the number of twigs in the tree are?

(a) 1 (b) 2 (c) 3 (d) 4

86. If there are 4 branches, 3 nodes then number of links in a co-tree are?

(a) 2 (b) 4 (c) 6 (d) 8

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