# Multiple Questions and Answers On Network Theory

**1) In any linear network, the elements like inductor, resistor and capacitor always_________**

**a.** Exhibit changes due to change in temperature

**b.** Exhibit changes due to change in voltage

**c.** Exhibit changes due to change in time

**d.** Remains constant irrespective of change in temperature, voltage and time

**ANSWER: (d) Remains constant irrespective of change in temperature, voltage and time**

**2) Which type of networks allow the physical separability of the network elements (resistors, inductors & capacitors) for analysis purpose?**

**a.** Lumped Networks

**b.** Distributed Networks

**c.** Unilateral Networks

**d.** Bilateral Networks

**ANSWER: (a) Lumped Networks**

**3) Which law plays a significant role in the loop analysis of the network?**

**a.** KCL

**b.** KVL

**c.** Law of Superposition Theorem

**d.** None of the above

**ANSWER: (b) KVL**

**4) How is the loop analysis different in application/functioning level as compared to Kirchoff’s law?**

**a.** Utilization of loop currents instead of branch currents for writing equations

**b.** Capability of branch current to carry multiple networks

**c.** Reduction in the number of unknowns for complex networks

**d.** All of the above

**ANSWER: (d) All of the above**

**5) Which theorem assists in replacement of an impedance branch over the network by the other network comprising different circuit components, without affecting the V-I relations throughout the entire network?**

**a.** Superposition Theorem

**b.** Compensation Theorem

**c.** Substitution Theorem

**d.** Maximum Power Transfer Theorem

**ANSWER: (a) Substitution Theorem**

**6) What should be done, if the dependent current and voltage sources are present in a circuit while applying ‘Superposition Theorem’?**

**a.** Replace them by open circuit

**b.** Replaced them by short circuit

**c.** Keep in their original form without replacing by either open or short circuits

**d.** None of the above

**ANSWER: Keep in their original form without replacing by either open or short circuits**

**7) Which is the correct sequential order of steps to be undertaken while applying Thevenin’s theorem?**

A. Calculation of Thevenin’s equivalent voltage

B. Removal of branch impedance through which required current is to be estimated

C. Estimation of equivalent impedance between two terminals of the branch

D. Estimation of branch current by schematic representation of Thevenin’s equivalent circuit

**a.** A, C, B, D

**b.** B, A, C, D

**c.** D, A, C, B

**d.** B, C, D, A

**ANSWER: B, A, C, D**

**9) Which among the below specified assertions are precisely related to the conditions applicable for a path to be an improper subgraph?**

A. Incidence of a single branch at a terminating node

B. Incidence of two branches at the remaining nodes

**a.** A is true & B is false

**b.** A is false & B is true

**c.** Both A & B are true

**d.** Both A & B are false

**ANSWER: (c) Both A & B are true**

**10) How many number of minimum end nodes or terminal nodes are involved in a tree, according to its properties?**

**a.** Only one

**b.** Two

**c.** Four

**d.** Infinite

**ANSWER: (b) Two**

**11) What will be the value of a rectangular (complete incidence) matrix, if an associated branch is oriented towards the node?**

**a.** 1

**b.** -1

**c.** 0

**d.** Not defined (∞)

**ANSWER:(b) -1**

**12) According to the linear graph theory, the number of possible trees is always equal to the determinant of product of ______**

**a.** Only complete incidence matrix

**b.** Reduced incidence matrix & its transpose

**c.** Cut-Set matrix

**d.** Tie-set matrix

**ANSWER: (b) Reduced incidence matrix & its transpose**

**13) Consider the mathematical representation of n ^{th} order differential equation given below. What does the notation v(t) indicate in it?**

a_{0} (d^{n} i/dt^{n}) + a_{1} (d^{n -1} i /dt^{n-1}) + …… +a_{ n-1} (di / dt) + a_{n} i = v(t)

**a.** Independent variable

**b.** Input or forcing function

**c.** Excitation

**d.** All of the above

**ANSWER: (d) All of the above**

**14) If a differential equation is said to be homogeneous, what would be the value of a forcing function?**

**a.** 0

**b.** 1

**c.** ∞

**d.** -1

**ANSWER: (a) 0**

**15) Which notation of instant implies that the unchanged condition of network is about to change?**

**a.** t(0)^{+}

**b.** t(0)^{–}

**c.** t^{*}

**d.** t^{ˆ}

**ANSWER: (b) t(0) ^{–}**

**16) Which elements behave as an open circuit especially under the consideration of d.c. quantities?**

**a.** Inductors

**b.** Resistors

**c.** Capacitors

**d.** All of the above

**ANSWER: (c) Capacitors**

**17) What would be the value of power factor for series RLC circuit under the resonance phenomenon?**

**a.** 0

**b.** 0.5

**c.** 1

**d.** Infinity

**ANSWER: (c) 1**

**18) Which among the following get/s cancelled under the resonance condition in a.c. circuits, if inductive and capacitive reactances are in parallel?**

**a.** Reactance

**b.** Susceptance

**c.** Resistance

**d.** All of the above

**ANSWER: (b) Susceptance**

**19) Which among the following condition is true at the resonance?**

**a.** X_{c} > X_{L}

**b.** X_{c} = X_{L}

**c.** X_{c} < X_{L}

**d.** None of the above

**ANSWER: (b) X _{c} = X_{L}**

**20) Reactance curve is basically a graph of individual reactances verses __________**

**a.** Frequency

**b.** Phase

**c.** Amplitude

**d.** Time period

**ANSWER: (a) Frequency**

**21) Which type of impedance in asymmetrical network is estimated at a single pair of network terminals especially in the chain of infinite networks?**

**a.** Image impedance

**b.** Iterative impedance

**c.** Characteristic impedance

**d.** All of the above

**ANSWER: (b) Iterative impedance**

**22) Where do the ‘correctly terminated asymmetrical networks’ show termination at both the ports of network?**

**a.** In image impedances

**b.** In iterative impedances

**c.** In characteristic impedances

**d.** All of the above

**ANSWER: (a) In image impedances**

**23) Which unit is used for the measurement of an insertion loss?**

**a.** Neper

**b.** Weber

**c.** Ohm

**d.** Watt

**ANSWER: (a) Neper**

**24) How is an insertion loss represented in terms of power ratio?**

**a.** α = 10 log_{10} | P_{1} / P_{2} | decibel

**b.** α = 10 log_{10} | P_{2} / P_{1} | decibel

**c.** α = 20 log_{10} | P_{1} / P_{2} | decibel

**d.** α = 20 log_{10} | P_{2} / P_{1} | decibel

**ANSWER: (a) α = 10 log _{10} | P_{1} / P_{2} | decibel**

**25) Which type of filter is shown below?**

**a.** Low pass filter

**b.** High pass filter

**c.** Band pass filter

**d.** Band elimination filter

**ANSWER: (d) Band elimination filter**

**26) While designing a constant-k low pass filter (T-section) shown below, what would be the value of capacitor if L/2 = 20mH, R _{0} = 500 Ω and f_{c} = 5 kHz?**

**a.** 0.0635 μF

**b.** 0.10 μF

**c.** 0.1273 μF

**d.** 0.20 μF

**ANSWER: (c) 0.1273 μF**

**27) For a constant k type LPF with T- section, with the cut-off frequency of about 4kHz, what will be the value of stop-band attenuation at 8 kHz?**

**a.** 10.03 dB

**b.** 22.87 dB

**c.** 35.04 dB

**d.** 50.02 dB

**ANSWER: (b) 22.87 dB**

**28) Referring to the characteristics of π-section low pass filter given below, what would be the phase shift at 2kHz in the pass band?**

**a.** 0.7731 radian

**b.** 1.0471 radian

**c.** 2.551 radian

**d.** 3.991 radian

**ANSWER:(b) 1.0471 radian**

**29) Which type of attenuators provide a fixed amount of attenuation by allowing the user to vary the attenuation in multiple steps?**

**a.** Ladder attenuators

**b.** Variable-value attenuators

**c.** Pad attenuators

**d.** All of the above

**ANSWER: (a) Ladder attenuators**

**30) For the symmetrical ‘T’ attenuator shown below, what would be the value of shunt arm resistance with N = 10 & design impedance = 500 ohm?**

**a.** 51.21 ohm

**b.** 101.01 ohm

**c.** 305.90 ohm

**d.** 409.90 ohm

**ANSWER: (b) 101.01 ohm**

**31) Consider the assertions given below. Which of them is not a disadvantage of Laplace Transform?**

**a.** Unsuitability for data processing in random vibrations

**b.** Analysis of discontinuous inputs

**c.** Possibility of conversion s = jω is only for sinusoidal steady state analysis

**d.** Inability to exist for few Probability Distribution Functions

**ANSWER: (b) Analysis of discontinuous inputs**

**32) What does ‘σ’ indicate in the equation of complex frequency variable s = σ + jω while defining the laplace transform?**

A. Attenuation constant

B. Damping factor

C. Propagation constant

D. Phase constant

**a.** A & B

**b.** C & D

**c.** B & C

**d.** B & D

**ANSWER: (a) A & B**

**33) How does the ‘σ’ of complex frequency variable appear in time domain?**

**a.** As a linear power

**b.** As a reactive power

**c.** As an exponential power

**d.** As an iterative power

**ANSWER: (c) As an exponential power**

**34) In the pictorial schematic shown below, what would be the equation of time domain behaviour produced due to complex frequency variable for σ > 0?**

**a.** e^{σt} sin ωt

**b.** e^{σt} cos ωt

**c.** e^{σt} sin ωt + e^{σt} cos ωt

**d.** e^{σt} sin ωt – e^{σt} cos ωt

**ANSWER: (b) e ^{σt} cos ωt**

**35) In the circuit, the driving point impedance is (s + 5) / (s ^{2} + 5s + 1). Hence, the driving point admittance of the circuit is __________**

**a.** (s + 5)

**b.** (s^{2} + 5s + 1)

**c.** (s + 5) x (s^{2} + 5s + 1)

**d.** (s^{2} + 5s + 1) / (s + 5)

**ANSWER: (d) (s ^{2} + 5s + 1) / (s + 5)**

**36) Compute the voltage ratio transfer function for the network shown below. Assume that the current flowing through the branch between node ‘a’ & ‘Q’ is (I _{a} + 4 I_{a}) i.e. 5I_{a}**

**a.** -3/7

**b.** -5/11

**c.** -3/11

**d.** -5/7

**ANSWER: (b) -5/11**

**37) Transfer admittance function is the ratio of Laplace transforms of ________**

**a.** Current at one port to voltage at other port

**b.** Voltage at one port to current at other port

**c.** Current at one port to current at other port

**d.** Voltage at one point to voltage at other port

**ANSWER: (a) Current at one port to voltage at other port**

**38) When a network function is expressed as a ratio of Laplace transforms of output to input variables of a system, then it is regarded as _______**

**a.** System function

**b.** Transfer function

**c.** Both a and b

**d.** None of the above

**ANSWER: (c) Both a and b**

**39) What does the connectivity of energy source at the port of network known as?**

**a.** Driving Point

**b.** Transfer Point

**c.** Both a and b

**d.** None of the above

**ANSWER: (a) Driving Point**

**40) For the network given below, what would be the value of ‘z _{22}‘, if the estimated z-parameters are ‘z_{11}‘ = 30 and ‘z_{12}‘ = ‘z_{21}‘ = 10?**

**a.** 10

**b.** 20

**c.** 30

**d.** 40

**ANSWER: (d) 40**

**41) What is the potential value of a reference or datum node used in the node analysis of a network?**

**a.** Zero

**b.** Unity

**c.** Greater than zero but less than infinity

**d.** Unpredictable

**ANSWER: (a) Zero**

**42) 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 polarities similar to that of two sources

**b.** Addition of two sources with opposite polarity

**c.** Difference between the two sources with polarities similar to that of two sources

**d.** Difference between the two sources with polarities similar to that of greater among the two sources

**ANSWER: (a) Addition of two sources with polarities similar to that of two sources**

**43) What should be the value of resistance for the circuit diagram shown below?**

**a.** Zero

**b.** Infinity

**c.** Unity

**d.** Cannot be predicted

**ANSWER: (a) Zero**

**44) What should be the value of I _{2} in accordance to mesh current method for the below drawn circuit diagram?**

**a.** 1.39 A

**b.** 1.63 A

**c.** 2.33 A

**d.** 5 A

**ANSWER: (b) 1.63 A**

**45) Which among the following is also regarded as ‘Dual of Thevenin’s Theorem’?**

**a.** Norton’s Theorem

**b.** Superposition Theorem

**c.** Millman’s Theorem

**d.** Maximum Power Transfer Theorem

**ANSWER: (a) Norton’s Theorem**

**46) What would be the nature of ‘Z _{L}‘, if ‘Z_{eq}‘ reactance is inductive according to ‘Maximum power transfer theorem’?**

**a.** Inductive

**b.** Capacitive

**c.** Resistive

**d.** All of the above

**ANSWER: (b) Capacitive**

**47) Which value of load impedance (Z _{L}) is necessary to be connected across the terminals R-S for maximum power transfer in the network shown below ?**

**a.** 5 + j5 Ω

**b.** 5 – j5 Ω

**c.** 10 + j10 Ω

**d.** 10 – j10 Ω

**ANSWER: (d) 10 – j10 Ω**

**48) What is the value of impedance ‘Z _{2}‘ according to Miller’s theorem for the network shown below?**

**a.** Z.K /K-1

**b.** Z /1-K

**c.** Z /K-1

**d.** Z-1 /K

**ANSWER: (a) Z.K /K-1**

**49) What will be the number of trees, if the graph exhibits reduction in the form of reduced incident matrix given below?**

**a.** 16

**b.** 24

**c.** 26

**d.** 28

**ANSWER: (b) 24**

**50) How many fundamental cutsets will be generated for a graph with ‘n’ number of nodes?**

**a.** n+1

**b.** n-1

**c.** n^{2}(n-1)

**d.** n/ n-1

**ANSWER: (b) n-1**

**51) Which parameter should be essentially equal to the number of nodes in the network in accordance to the principle of duality?**

**a.** Total impedance

**b.** Total admittance

**c.** Number of meshes

**d.** Number of voltage sources

**ANSWER: (c) Number of meshes**

**52) Consider the assertions given below. Which among them do/does not specify/ies the property of ‘Complete Incidence Matrix’?**

**a.** Determinant of a loop of a complete incidence matrix is always zero

**b.** Addition of all entries in any column should never be equal to zero

**c.** Rank of connected or oriented graph is always ‘n-1’

**d.** All of the above

**ANSWER: (b) Addition of all entries in any column should never be equal to zero**

**53) Which type of network response exhibits its behaviour by taking into consideration the effect of time associated with it?**

**a.** Zero input response

**b.** Zero state response

**c.** Both a and b

**d.** None of the above

**ANSWER: (b) Zero state response**

**54) From the diagram given below showing characteristics of voltage across resistor and inductor with respect to time, what conclusion can be drawn due to exponential growth of current through inductor?**

**a.** Voltage across resistor and inductor increases

**b.** Voltage across resistor and inductor decreases

**c.** Voltage across resistor increases but decreases across inductor

**d.** Voltage across resistor decreases but increases across inductor

**ANSWER: (c)Voltage across resistor increases but decreases across inductor**

**55) Consider the circuit drawn below. What would be the value of i(0 ^{–}) especially when the inductor acts as a short circuit?**

**a.** 0.3 A

**b.** 2 A

**c.** 5 A

**d.** 10 A

**ANSWER: (b) 2 A**

**56) How many seconds will be required for the current i(t) to become one half of its initial value after t = 0 in the below drawn network **

**a.** 866 μs

**b.** 1039 μs

**c.** 1200 μs

**d.** 1849 μs

**ANSWER: (b) 1039 μs**

**57) How do the series resonant circuit behave under the resonance condition?**

**a.** Current amplifier

**b.** Transconductance

**c.** Voltage regulator

**d.** Voltage amplifier

**ANSWER: (d) Voltage amplifier**

**58) If an a.c. signal generator drives a series RLC circuit, then the circuit undergoes resonance only due to variation in __________**

**a.** Supply voltage

**b.** Series resistance

**c.** Supply frequency

**d.** Phase angle

**ANSWER: (c) Supply frequency**

**59) The current leads supply voltage if a series resonant circuit exhibits its operation__________ the resonant frequency**

**a.** Above

**b.** Below

**c.** Equal to

**d.** None of the above

**ANSWER: (b) Below**

**60) What would be the value of impedance of a parallel resonant circuit at antiresonance condition?**

**a.** Resistive & maximum

**b.** Resistive & minimum

**c.** Reactive & maximum

**d.** Reactive & minimum

**ANSWER: (a) Resistive & maximum**

**61) What would be the characteristic impedance of a T-section for symmetrical network shown below?**

**a.** 300.15 ohm

**b.** 529.15 ohm

**c.** 715.15 ohm

**d.** 900.15 ohm

**ANSWER: (b) 529.15 ohm**

**62) Consider the symmetrical T-network shown below. What will be the value of propagation constant, if characteristic impedance is estimated to be Z _{0} = 850.64 ohm?**

**a.** 0.2824 neper

**b.** 0.1412 neper

**c.** 0.0706 neper

**d.** 0.0353 neper

**ANSWER: (b) 0.1412 neper**

**63) Consider the below mentioned assumptions of two symmetrical T networks in cascade configuration. What will be the value of current flowing through terminating impedance for the network configuration shown below?**

Assumptions:

n = -2,

? = 1.5,

I_{s} = 0.6 A

**a.** 0.0112 A

**b.** 0.0298 A

**c.** 0.04145 A

**d.** 0.0812 A

**ANSWER: (b) 0.0298 A**

**64) If a network comprises purely resistive elements, what will it provide from the following?**

**a.** Attenuation

**b.** Phase Shift

**c.** Both a and b

**d.** None of the above

**ANSWER: (a) Attenuation**

**65) What do the high pass filters generally comprise of?**

A. Capacitive series arm

B. Capacitive shunt arm

C. Inductive series arm

D. Inductive shunt arm

**a.** A & D

**b.** A & C

**c.** B & C

**d.** B & D

**ANSWER: (a) A & D**

**66) For the design of prototype high pass filter T section, what would be the value of inductor if design impedance and cut-off frequency are 600 ohm and 1500 Hz respectively?**

**a.** 19.89 mH

**b.** 31.83 mH

**c.** 40.13 mH

**d.** 51.83 mH

**ANSWER: (b) 31.83 mH**

**67) In band elimination filter, the frequency of resonance of individual arms is geometric _________**

**a.** Mean of two cut-off frequencies

**b.** Difference of two cut-off frequencies

**c.** Product of two cut-off frequencies

**d.** Division of two cut-off frequencies

**ANSWER: (a) Mean of two cut-off frequencies**

**68) Which value of ‘m’ is selected in a composite filter, while connecting the terminating sections in order to acquire proper impedance matching and constant characteristic impedance throughout the passband?**

**a.** 0.3

**b.** 0.6

**c.** 0.9

**d.** 0.12

**ANSWER: (b) 0.6**

**69) Referring to the schematic of symmetrical π attenuator below, what will be the computational value of attenuation in neper, if D = 20 dB & R _{0} = 400 ohm?**

**a.** 10

**b.** 20

**c.** 40

**d.** 80

**ANSWER: (a) 10**

**70) Why are the variable attenuators applicable for radio broadcasting purposes? **

**a.** For speed control

**b.** For volume control

**c.** For time control

**d.** For power control

**ANSWER: (b) For volume control**

**71) With reference to the diagram shown below, by how many instants is the ramp function shifted or delayed?**

**a.** T

**b.** t – T

**c.** 1

**d.** -T

**ANSWER: (a) T**

**72) Consider a function f(t) that satisfies the differential equation given below. What equation will be generated by taking Laplace transform and replacing the terms f(0 ^{–}) & f'(0^{–}) by zero?**

[d^{2} f(t) / dt^{2}] + 5 [df(t) / dt ] + 6 f (t) = 10

**a.** [S^{2} F(s) + 5s F(s)+6 F(s)] = 10/s

**b.** [S^{2} F(s) + 5s F(s) – 6 F(s)] = 10/s

**c.** [S^{2} F(s) – 5s F(s) + 6 F(s)] = 10/s

**d.** [S^{2} F(s) – 5s F(s) – 6 F(s)] = 10/s

**ANSWER: (a) [S ^{2} F(s) + 5s F(s)+6 F(s)] = 10/s**

**73) In accordance to Laplace domain theory, the transform admittance of resistance is _______**

**a.** Impedance

**b.** Conductance

**c.** Inductance

**d.** Capacitance

**ANSWER: (b) Conductance**

**74) From the circuit diagram shown below, what would be the value of transform impedance of a single capacitor in Laplace domain?**

**a.** 1 / sC

**b.** sC

**c.** sC – 1

**d.** sC / 1+ sC

**ANSWER: (a) 1 / sC**

**75) What does the value of constant ‘k’ represent in the factorized form of network equation given below?
H(s) = [k (s – z _{1}) (s – z_{2}) —– (s – z_{m})] / [(s – p_{1}) (s – p_{2}) ….. (s – p_{n})]**

A. System gain factor

B. Scale factor

C. Vector factor

D. System quality factor

**a.** A & B

**b.** C & D

**c.** A & C

**d.** B & D

**ANSWER: (a) A & B**

**76) If the complex system function is analytic in nature, the points in s-plane are regarded as ________**

**a.** Ordinary points

**b.** Singular points

**c.** Multiple points

**d.** All of the above

**ANSWER: (a) Ordinary points**

**77) Which among the following belong/s to the category of critical frequency?**

**a.** Poles

**b.** Zeros

**c.** Both a and b

**d.** None of the above

**ANSWER: (c) Both a and b**

**78) What is an ideal value of network function at poles?**

**a.** Zero

**b.** Unity

**c.** Infinity

**d.** Finite and non-zero

**ANSWER: (c) Infinity**

**79) Which elements act as an independent variables in Y-parameters?**

**a.** Current

**b.** Voltage

**c.** Both a and b

**d.** None of the above

**ANSWER: (b) Voltage**

**80) Which among the following is regarded as short circuit forward transfer admittance?**

**a.** y_{11}

**b.** y_{12}

**c.** y_{21}

**d.** y_{22}

**ANSWER: (c) y _{21}**

**81) Under which conditions does the source transformation technique remain directly unapplicable?**

**a.** Only in the absence of impedance in series with a voltage source

**b.** Only in the absence of impedance in parallel with a current source

**c.** Both a and b

**d.** None of the above

**ANSWER: (c) Both a and b**

**82) 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

**ANSWER: (a) Node method**

**83) Which operation is likely to get executed or performed by Millman’s theorem in terms of converting the voltage or current sources into a single equivalent voltage or current source?**

**a.** Subtraction

**b.** Combination

**c.** Differentiation

**d.** Integration

**ANSWER: (b) Combination**

**84) Why does the Superposition theorem not applicable to power?**

**a.** Because it is proportional to square of current and current is a non-linear function

**b.** Because it is proportional to square of voltage and voltage is a non-linear function

**c.** Both a and b

**d.** None of the above

**ANSWER: (a) Because it is proportional to square of current and current is a non-linear function**

**85) What would be an order of branch impedance matrix for the below stated KVL equilibrium equation on the basis of loop or mesh analysis?**

E = B (V_{s} – Z_{b} I_{s})

**a.** b x 1

**b.** b x b

**c.** b-n+1) x 1

**d.** (b-n+1) x b

**ANSWER: (b) b x b**

**86) According to the graph theory of loop analysis, how many equilibrium equations are required at a minimum level in terms of number of branches (b) and number of nodes (n) in the graph?**

**a.** n-1

**b.** b+(n-1)

**c.** b-(n-1)

**d.** b/ n-1

**ANSWER: (c) b-(n-1)**

**87) What would be the nature of roots for undamped type of circuits with sustained oscillations?**

**a.** Purely imaginary

**b.** Real, equal & negative

**c.** Complex conjugate with negative real part

**d.** Real, unequal & negative

**ANSWER: (a) Purely imaginary**

**88) What will be the value of the time required by the response to reach 50% of its steady state value for second order system?**

**a.** π – θ /ω_{d}

**b.** π / ω_{d}

**c.** 4 / ξ ω_{n}

**d.** (1+ 0.7 ξ) /ω_{n}

**ANSWER: (d) (1+ 0.7 ξ) /ω _{n}**

**89) What will be the nature of impedance at a frequency below the antiresonant frequency?**

**a.** Capacitive

**b.** Inductive

**c.** Reactive

**d.** Resistive

**ANSWER: (b) Inductive**

**90) If the value of resonant frequency is 50 kHz in a series RLC circuit along with the bandwidth of about 1 kHz, then what would be the value of quality factor?**

**a.** 5

**b.** 50

**c.** 100

**d.** 500

**ANSWER: (b) 50**

**91) What would be the value of attenuation constant especially for the network consisting of purely reactive elements?**

**a.** 0

**b.** 1

**c.** -1

**d.** Infinity

**ANSWER: (a) 0**

**92) Suppose that a network consists of purely resistive elements, what will be the value of propagation constant (generated output) in terms of attenuation constant and phase constant from the following?**

**a.** γ = α + j0

**b.** γ = 0 + jβ

**c.** γ = 0 – jβ

**d.** γ = α – j0

**ANSWER: γ = α + j0**

**93) It is possible to overcome the drawback of m-derived filter by connecting number of sections in addition to prototype & m-derived sections with terminating __________**

**a.** One-fourth sections

**b.** Half sections

**c.** Square of three-fourth sections

**d.** Full sections

**ANSWER: (b) Half sections**

**94) What is an ideal value of attenuation for the frequencies in pass band especially for a cascade configuration?**

**a.** Zero

**b.** Unity

**c.** Infinity

**d.** Unpredictable

**ANSWER:(a) Zero**

**95) Variable attenuators exhibit variable attenuation but constant __________**

**a.** Input impedance

**b.** Output impedance

**c.** Both a and b

**d.** None of the above

**ANSWER: (c) Both a and b**

**96) In accordance to the circuit configuration of bridged ‘T’ variable attenuator below, how many resistors should be varied in order to achieve variable attenuation?**

**a.** Only one

**b.** Two

**c.** Three

**d.** Four

**ANSWER: (b) Two**

**97) If the value of (P _{1} / P_{2}) in power ratio expressed in terms of dB is greater than unity, what does ‘D’ indicate in the network?**

**a.** Power loss

**b.** Power gain

**c.** Power stability

**d.** Power saving

**ANSWER: (a) Power loss**

**98) What will be the driving point impedance of Laplace domain network shown below?**

**a.** (10s^{2} + 5.25s + 1.5) / (s+0.125)

**b.** (6s^{2} + 2.25s + 1.5) / (s+0.25)

**c.** (5s^{2} + 2.25s + 1.5) / (s+0.16)

**d.** (8s^{2} + 2.25s + 1.5) / (s+0.8)

**ANSWER: (a) (10s ^{2} + 5.25s + 1.5) / (s+0.125)**

**99) Consider the RC circuit shown below. What will be the value of time constant for RC circuit?**

**a.** 0.25 sec

**b.** 0.50 sec

**c.** 1 sec

**d.** 2 sec

**ANSWER: (c) 1 sec**

**100) What would be the value of i(t) especially for t > 0 in the RC circuit shown below? [Assume that the polarities of v _{c} (0^{–}) are similar to the drop across capacitor due to i(t)]**

**a.** -2.125 e^{-1t} A

**b.** -4.125 e^{-2t} A

**c.** -8 e^{-4t} A

**d.** -10 e^{-5t} A

**ANSWER: (a) -2.125 e ^{-1t} A**

**101) For the pole-zero plot given below, what would be the value of system function H(s), if the d.c. gain of the system is 20?**

**a.** 10 (s + 4) / (s + 1) (s^{2} + 6s – 10)

**b.** 20 (s – 4) / (s + 3) (s^{2} _ 6s +10)

**c.** 40 (s + 4) / (s + 3) (s^{2} – 6s – 10)

**d.** 50 (s + 4) / (s + 1) (s^{2} + 6s +10)

**ANSWER: (d) 50 (s + 4) / (s + 1) (s ^{2} + 6s +10)**

**102) Which oscillations will be generated in the time domain response, if complex conjugate poles are present with negative real part?**

**a.** Damped oscillations

**b.** Undamped oscillations

**c.** Sustained oscillations

**d.** None of the above

**ANSWER: (a) Damped oscillations**

**103) Which among the below mentioned cases are responsible for generating the oscillations with increasing amplitude in time domain response of system function?**

A. Complex poles with positive real part

B. Complex poles with negative real part

C. Repeated poles on imaginary axis

D. Repeated poles on real axis

**a.** A & C

**b.** B & D

**c.** B & C

**d.** A & D

**ANSWER:(a) A & C**

**104) How is the short circuit reverse transfer admittance (y _{12}) calculated in terms of current and voltage ratio?**

**a.** V_{2}/ I_{1} (keeping I_{2} = 0)

**b.** I_{2}/ V_{1} (keeping V_{2} = 0)

**c.** I_{1}/ V_{2} (keeping V_{1} = 0)

**d.** V_{1}/ I_{2} (keeping I_{1} = 0)

**ANSWER: (c) I _{1}/ V_{2} (keeping V_{1} = 0)**

**105) An open circuit reverse voltage gain in h-parameters is a unitless quantity and generally equivalent to ________**

**a.** V_{1} / I_{1} (keeping V_{2} = 0)

**b.** I_{2} / I_{1} (keeping V_{2} = 0)

**c.** V_{1} / V_{2} (keeping I_{1} = 0)

**d.** I_{2} / V_{2} (keeping I_{1} = 0)

**ANSWER: (c) V _{1} / V_{2} (keeping I_{1} = 0)**

**106) Which is the correct condition of symmetry observed in z-parameters?**

**a.** z_{11} = z_{22}

**b.** z_{11} = z_{12}

**c.** z_{12} = z_{22}

**d.** z_{12} = z_{21}

**ANSWER: (a) z _{11} = z_{22}**

**107) Which among the following represents the precise condition of reciprocity for transmission parameters?**

**a.** AB – CD = 1

**b.** AD – BC = 1

**c.** AC – BD = 1

**d.** None of the above

**ANSWER: (b) AD – BC = 1**

**108) If the two ports are connected in cascade configuration, then which arithmetic operation should be performed between the individual transmission parameters in order to determine overall transmission parameters?**

**a.** Addition

**b.** Subtraction

**c.** Multiplication

**d.** Division

**ANSWER: (c) Multiplication**

**109) If z-parameters are z _{11} = 40, z_{22} = 50 and z_{12} = z_{21} = 20, what would be the value of y_{22}in the matrix form of y-parameters given below?**

**a.** 4 / 160

**b.** 5 / 160

**c.** 10 / 160

**d.** 15 / 150

**ANSWER: (a) 4 / 160**