All Electronics & Telecommunication MCQs

Browse Electronics & Telecommunication Engineering MCQs with four options, hidden answers, concise explanations and references where available. Questions are organized in pages of up to 100 for focused practice.

Question 1708
Network TheoryNetwork Topology

For an oriented graph, each column of the node-branch incidence matrix corresponding to an ordinary branch contains?

  • AOne +1 and one -1
  • BTwo +1 entries only
  • COne nonzero entry only
  • DAll zero entries
Report an error
Correct Answer: A. One +1 and one -1
Explanation: An oriented branch leaves one node and enters another, so its incidence-matrix column has one +1 and one -1 under a consistent sign convention.
Reference: Standard network theory: incidence matrix structure
Question 1710
Network TheoryNetwork Topology

A tie-set matrix is primarily used to express branch currents in terms of?

  • AIndependent loop currents
  • BNode voltages only
  • CBranch powers
  • DCut-set voltages only
Report an error
Correct Answer: A. Independent loop currents
Explanation: Tie-set or fundamental-loop analysis relates branch currents to a set of independent loop currents.
Reference: Standard network theory: tie-set matrix
Question 1714
Network TheoryNetwork Theorems

For a linear circuit containing several independent sources, superposition is applied to calculate?

  • AVoltages and currents, not power directly
  • BPower directly by adding individual source powers at an element
  • CEquivalent resistance only
  • DFrequency only
Report an error
Correct Answer: A. Voltages and currents, not power directly
Explanation: Superposition applies to linear response quantities such as voltage and current. Power is nonlinear in voltage/current and cannot generally be superposed directly.
Reference: Standard network theory: superposition limitation
Question 1725
Network TheoryAC Circuit Analysis

For Z=3-j4 ohm, the impedance angle is closest to?

  • A-53.1 degrees
  • B+53.1 degrees
  • C-36.9 degrees
  • D+36.9 degrees
Report an error
Correct Answer: A. -53.1 degrees
Explanation: The angle is tan^-1(-4/3)≈-53.1 degrees, indicating capacitive behavior.
Reference: Standard network theory: impedance phase numerical
Question 1736
Network TheoryThree-Phase Circuits

In the two-wattmeter method, if the balanced load has unity power factor, the two wattmeters ideally read?

  • AEqual positive values
  • BEqual and opposite values
  • COne zero and one positive value
  • DBoth zero
Report an error
Correct Answer: A. Equal positive values
Explanation: At unity power factor phi=0, the readings are proportional to cos(30°-phi) and cos(30°+phi), so they are equal and positive.
Reference: Standard network theory: two-wattmeter unity power factor
Question 1740
Network TheoryAC Power

A load has complex power S=3+j4 kVA. Its power factor is?

  • A0.4 lagging
  • B0.6 lagging
  • C0.8 lagging
  • D1.0
Report an error
Correct Answer: B. 0.6 lagging
Explanation: |S|=5 kVA and power factor=P/|S|=3/5=0.6. Positive Q denotes an inductive, lagging load.
Reference: Standard network theory: complex power factor numerical
Question 1744
Network TheoryLaplace Transform

The final-value theorem gives f(infinity), when applicable, as?

  • Alim s->infinity sF(s)
  • Blim s->0 sF(s)
  • Clim s->0 F(s)/s
  • Dlim s->infinity F(s)
Report an error
Correct Answer: B. lim s->0 sF(s)
Explanation: If the required pole conditions are satisfied, f(infinity)=lim as s approaches zero of sF(s).
Reference: Standard network theory: final-value theorem
Question 1745
Network TheoryLaplace Transform

The final-value theorem is not valid for a response whose sF(s) has?

  • AAll poles strictly in the left-half plane
  • BA pole in the right-half plane
  • CNo finite poles
  • DOnly negative real poles
Report an error
Correct Answer: B. A pole in the right-half plane
Explanation: A right-half-plane pole produces a growing mode, so the response does not approach a finite final value and the final-value theorem cannot be used in its standard form.
Reference: Standard network theory: final-value theorem applicability
Question 1746
Network TheoryTransient Analysis

The natural response of a linear circuit is produced by?

  • AStored energy and initial conditions with independent sources set to zero
  • BIndependent sources only with all stored energy removed
  • COnly sinusoidal sources
  • DOnly dependent sources removed
Report an error
Correct Answer: A. Stored energy and initial conditions with independent sources set to zero
Explanation: The natural or zero-input response is due to energy initially stored in capacitors and inductors after independent sources are set to zero.
Reference: Standard network theory: natural response
Question 1747
Network TheoryTransient Analysis

The zero-state response of a linear circuit is the response when?

  • AAll independent sources are zero but initial energy is retained
  • BInitial conditions are zero and external sources act
  • CBoth sources and initial conditions are zero
  • DOnly dependent sources are removed
Report an error
Correct Answer: B. Initial conditions are zero and external sources act
Explanation: Zero-state response is caused by external excitation with all independent initial energy-storage conditions set to zero.
Reference: Standard network theory: zero-state response
Question 1748
Network TheoryTransient Analysis

The complete response of a linear circuit can be expressed as?

  • ANatural response plus forced response
  • BResistance plus reactance only
  • CVoltage response minus current response
  • DInitial value multiplied by final value
Report an error
Correct Answer: A. Natural response plus forced response
Explanation: A linear circuit's complete response is commonly decomposed into natural (transient) and forced components.
Reference: Standard network theory: complete response
Question 1749
Network TheoryTransient Analysis

For a stable first-order circuit excited by a constant DC source, the natural-response component as t approaches infinity?

  • AGrows without bound
  • BApproaches zero
  • CBecomes equal to the source voltage in every circuit
  • DOscillates indefinitely
Report an error
Correct Answer: B. Approaches zero
Explanation: A stable first-order natural term has the form Ke^(-t/tau), which decays to zero as time increases.
Reference: Standard network theory: natural response decay
Question 1754
Network TheorySecond-Order Circuits

In an overdamped second-order circuit, the characteristic roots are typically?

  • ATwo distinct negative real roots for a stable passive circuit
  • BA repeated imaginary pair
  • CA complex-conjugate pair with zero real part
  • DOne root only at the origin
Report an error
Correct Answer: A. Two distinct negative real roots for a stable passive circuit
Explanation: Overdamping gives two distinct real roots; in a stable passive circuit both are negative and produce nonoscillatory decaying exponentials.
Reference: Standard network theory: overdamped roots
Question 1759
Network TheoryNetwork Duality

Under network duality, an inductor is dual to a?

  • AResistor
  • BCapacitor
  • CVoltage source
  • DTransformer
Report an error
Correct Answer: B. Capacitor
Explanation: Inductance and capacitance are dual energy-storage elements.
Reference: Standard network theory: inductor-capacitor duality
Question 1760
Network TheoryNetwork Duality

The dual of Kirchhoff’s voltage law is?

  • AOhm's law
  • BKirchhoff's current law
  • CFaraday's law
  • DMaximum power theorem
Report an error
Correct Answer: B. Kirchhoff's current law
Explanation: KVL constrains loop voltages, while its dual KCL constrains node currents.
Reference: Standard network theory: KVL-KCL duality
Question 1761
Network TheoryNetwork Theorems

The substitution theorem permits a branch of a network to be replaced by another element or source provided the replacement maintains the same?

  • ABranch voltage and current
  • BTotal number of nodes only
  • COperating frequency only
  • DPower factor of every other branch only
Report an error
Correct Answer: A. Branch voltage and current
Explanation: At a specified operating condition, substitution is valid when the replacement preserves the original branch terminal voltage and current.
Reference: Standard network theory: substitution theorem
Question 1762
Network TheoryNetwork Theorems

The compensation theorem is useful for determining changes in network currents and voltages caused by a change in?

  • AA branch impedance
  • BThe number of graph nodes only
  • CSource frequency with every impedance fixed
  • DReference-node labeling
Report an error
Correct Answer: A. A branch impedance
Explanation: The compensation theorem evaluates incremental response when a branch impedance changes in a linear bilateral network.
Reference: Standard network theory: compensation theorem
Question 1763
Network TheoryNetwork Theorems

If a branch carrying current I has its impedance increased by Delta Z, the compensating source magnitude used in the compensation theorem is proportional to?

  • AI/Delta Z
  • BI Delta Z
  • CI squared divided by Delta Z
  • DDelta Z/I squared
Report an error
Correct Answer: B. I Delta Z
Explanation: The compensating voltage magnitude is I Delta Z, with polarity chosen according to the theorem's replacement convention.
Reference: Standard network theory: compensation theorem relation
Question 1764
Network TheoryNetwork Synthesis

For a polynomial to be Hurwitz, all of its roots must lie in which region, allowing simple j-omega-axis roots only under the standard special conditions?

  • AClosed left-half plane
  • BOpen right-half plane
  • COnly positive real axis
  • DOnly at the origin
Report an error
Correct Answer: A. Closed left-half plane
Explanation: A Hurwitz polynomial has no roots in the open right-half plane; permitted imaginary-axis roots are simple under the standard network-synthesis definition.
Reference: Standard network theory: Hurwitz polynomial
Question 1765
Network TheoryNetwork Synthesis

Which polynomial is Hurwitz?

  • As^2-3s+2
  • Bs^2+3s+2
  • Cs^2-1
  • Ds^2-2s+5
Report an error
Correct Answer: B. s^2+3s+2
Explanation: s^2+3s+2=(s+1)(s+2), whose roots -1 and -2 lie in the left-half plane.
Reference: Standard network theory: Hurwitz polynomial numerical
Question 1766
Network TheoryNetwork Synthesis

For a positive-real rational function, any poles on the j-omega axis must be?

  • AMultiple with complex residues
  • BSimple with real nonnegative residues
  • CAlways double poles
  • DLocated only in the right-half plane
Report an error
Correct Answer: B. Simple with real nonnegative residues
Explanation: A positive-real function may have simple imaginary-axis poles, and their residues must be real and nonnegative.
Reference: Standard network theory: positive-real pole condition
Question 1767
Network TheoryNetwork Synthesis

For a positive-real function F(s), complex poles and zeros must occur in?

  • AUnrelated locations
  • BComplex-conjugate pairs
  • COnly the right-half plane
  • DOnly at s=0
Report an error
Correct Answer: B. Complex-conjugate pairs
Explanation: Because a positive-real network function is real for real s, nonreal poles and zeros occur in complex-conjugate pairs.
Reference: Standard network theory: conjugate roots
Question 1768
Network TheoryNetwork Synthesis

An RC driving-point impedance has poles and zeros on the negative real axis that characteristically?

  • AInterlace
  • BAlways coincide
  • CAppear only as complex pairs
  • DLie only on the positive real axis
Report an error
Correct Answer: A. Interlace
Explanation: For an RC driving-point impedance, realizability imposes alternating or interlacing negative-real poles and zeros with the appropriate ordering.
Reference: Standard network theory: RC impedance synthesis
Question 1769
Network TheoryNetwork Synthesis

For an RL driving-point impedance, poles and zeros of a realizable simple ladder form are characteristically located on the?

  • APositive real axis
  • BNegative real axis
  • Cj-omega axis only
  • DUnit circle
Report an error
Correct Answer: B. Negative real axis
Explanation: RL driving-point functions have real nonpositive critical frequencies; their finite poles and zeros interlace on the negative real axis.
Reference: Standard network theory: RL impedance synthesis
Question 1770
Network TheoryNetwork Synthesis

A Foster realization is especially associated with expansion of a driving-point function into?

  • APartial fractions
  • BA Fourier series only
  • CA determinant of the incidence matrix
  • DA power series in time
Report an error
Correct Answer: A. Partial fractions
Explanation: Foster synthesis decomposes an immittance into partial-fraction terms that map to simple circuit sections.
Reference: Standard network theory: Foster synthesis principle
Question 1773
Network TheoryNetwork Synthesis

For a pure reactance one-port made only of ideal L and C elements, the real part of its impedance on the j-omega axis away from poles is?

  • APositive and frequency dependent
  • BNegative and frequency dependent
  • CZero
  • DAlways equal to 1 ohm
Report an error
Correct Answer: C. Zero
Explanation: An ideal lossless LC network absorbs zero average power, so its impedance is purely imaginary away from singularities.
Reference: Standard network theory: reactance function
Question 1778
Network TheoryNetwork Functions

If Z(s)=(s+2)/(s+5), the corresponding admittance Y(s) is?

  • A(s+2)/(s+5)
  • B(s+5)/(s+2)
  • C1/[(s+2)(s+5)]
  • Ds+7
Report an error
Correct Answer: B. (s+5)/(s+2)
Explanation: Admittance is the reciprocal of impedance, hence Y(s)=(s+5)/(s+2).
Reference: Standard network theory: immittance conversion numerical
Question 1779
Network TheoryNetwork Synthesis

A rational function whose numerator degree exceeds its denominator degree by more than one cannot directly represent the driving-point impedance of a finite passive RLC network because it violates the usual?

  • APositive-real realizability requirements
  • BKCL sign convention only
  • CNode numbering rule
  • DTransformer turns-ratio rule
Report an error
Correct Answer: A. Positive-real realizability requirements
Explanation: Finite passive RLC driving-point immittances are positive-real rational functions with constrained high-frequency behavior; an excessive degree difference is incompatible with those realizability conditions.
Reference: Standard network theory: realizability condition
Question 1782
Network TheoryMatrix Network Analysis

In a passive reciprocal resistive network, the nodal admittance matrix is typically?

  • ASkew-symmetric
  • BSymmetric
  • CAlways diagonal
  • DSingular after choosing a reference node in every case
Report an error
Correct Answer: B. Symmetric
Explanation: For a reciprocal resistive network, mutual admittance terms satisfy symmetry, so the reduced nodal admittance matrix is symmetric.
Reference: Standard network theory: reciprocal nodal matrix
Question 1783
Network TheoryMatrix Network Analysis

In a nodal admittance matrix, a diagonal element Yii is generally formed from?

  • AThe negative sum of all conductances incident at node i
  • BThe sum of conductances connected to node i
  • COnly the largest branch resistance
  • DThe product of all branch impedances
Report an error
Correct Answer: B. The sum of conductances connected to node i
Explanation: The diagonal entry is the sum of admittances incident on the corresponding node under the standard nodal formulation.
Reference: Standard network theory: nodal matrix diagonal
Question 1787
Network TheoryTwo-Port Networks

A reciprocal two-port has z12=3 ohm. What must z21 be?

  • A-3 ohm
  • B0 ohm
  • C3 ohm
  • D1/3 siemens
Report an error
Correct Answer: C. 3 ohm
Explanation: Reciprocity in z-parameters requires z12=z21, hence z21=3 ohm.
Reference: Standard network theory: z-parameter reciprocity numerical
Question 1795
Network TheoryNetwork Functions

A transfer function has poles at -1 and -10. Which pole normally dominates the long-time response if its mode is present?

  • APole at -10
  • BPole at -1
  • CBoth always decay at identical rates
  • DNeither pole affects settling
Report an error
Correct Answer: B. Pole at -1
Explanation: The pole closest to the imaginary axis, -1, has the slowest exponential decay and therefore dominates the long-time response.
Reference: Standard network theory: dominant pole
Question 1798
Network TheoryNetwork Functions

For H(s)=(s+4)/(s+8), the high-frequency gain approaches?

  • A0
  • B0.5
  • C1
  • D4
Report an error
Correct Answer: C. 1
Explanation: The numerator and denominator have equal degree and equal leading coefficients, so the limit as |s| tends to infinity is 1.
Reference: Standard network theory: high-frequency gain numerical
Question 1799
Network TheoryNetwork Functions

A network function has a pole at the origin. Its corresponding natural mode includes which behavior?

  • AA nondecaying constant term
  • BOnly an exponentially decaying term
  • COnly a growing sinusoid
  • DNo time-domain contribution
Report an error
Correct Answer: A. A nondecaying constant term
Explanation: A simple pole at s=0 corresponds to a constant time-domain mode rather than an exponentially decaying mode.
Reference: Standard network theory: pole at origin