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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 1603
Analog ElectronicsNoise in Analog Circuits

Noise figure of an amplifier quantifies degradation of?

  • ASignal-to-noise ratio from input to output
  • BDC voltage gain only
  • CTransistor beta only
  • DOscillation frequency only
Report an error
Correct Answer: A. Signal-to-noise ratio from input to output
Explanation: Noise figure compares input and output SNR and indicates how much additional noise the amplifier effectively contributes.
Reference: Standard analog electronics: noise figure
Question 1606
Analog ElectronicsAmplifier Fundamentals

A voltage amplifier intended to avoid loading a high-resistance signal source should ideally have?

  • AHigh input resistance
  • BVery low input resistance
  • CZero voltage gain
  • DInfinite output resistance only
Report an error
Correct Answer: A. High input resistance
Explanation: High input resistance draws little current from the source, minimizing loading and preserving the source voltage.
Reference: Standard analog electronics: amplifier input resistance
Question 1607
Analog ElectronicsAmplifier Fundamentals

A voltage amplifier intended to drive a low-resistance load with good voltage transfer should generally have?

  • ALow output resistance
  • BHigh output resistance
  • CZero input resistance
  • DNo power supply
Report an error
Correct Answer: A. Low output resistance
Explanation: Low output resistance minimizes voltage drop inside the amplifier when load current flows and improves voltage delivery to the load.
Reference: Standard analog electronics: amplifier output resistance
Question 1612
Network TheoryNetwork Topology

A fundamental loop is formed when?

  • AOne link is added to a tree
  • BOne twig is removed from every graph
  • CAll nodes are shorted together
  • DAll voltage sources are opened
Report an error
Correct Answer: A. One link is added to a tree
Explanation: A tree contains no closed path. Adding any one link to it creates exactly one fundamental loop.
Reference: Standard network theory: fundamental loops
Question 1615
Network TheoryNetwork Theorems

Tellegen’s theorem is fundamentally based on conservation of?

  • APower in a network satisfying KCL and KVL
  • BResistance only
  • CFrequency only
  • DMagnetic flux only
Report an error
Correct Answer: A. Power in a network satisfying KCL and KVL
Explanation: Tellegen's theorem states that the algebraic sum of instantaneous branch powers is zero for networks whose branch voltages and currents satisfy KVL and KCL.
Reference: Standard network theory: Tellegen theorem
Question 1616
Network TheoryNetwork Theorems

The reciprocity theorem is applicable to a linear bilateral network containing a single independent source when comparing?

  • AInterchanged excitation and response locations
  • BOnly total resistance with all sources removed
  • COnly nonlinear diode currents
  • DOnly transient initial conditions
Report an error
Correct Answer: A. Interchanged excitation and response locations
Explanation: Reciprocity states, under its applicable conditions, that interchanging the location of excitation and measured response gives the same transfer relationship.
Reference: Standard network theory: reciprocity theorem
Question 1617
Network TheoryNetwork Theorems

Millman’s theorem is particularly convenient for finding the voltage at a node connected to several parallel branches containing?

  • AVoltage sources with series impedances
  • BOnly ideal inductors in series
  • COnly dependent current sources with no impedance
  • DA single resistor only
Report an error
Correct Answer: A. Voltage sources with series impedances
Explanation: Millman's theorem combines multiple parallel source-impedance branches into a direct weighted expression for the common node voltage.
Reference: Standard network theory: Millman theorem
Question 1618
Network TheoryNetwork Theorems

Two parallel branches connect a node to ground. Branch 1 has a 10 V source in series with 5 ohm and branch 2 has a 5 V source in series with 5 ohm, with both source polarities tending to make the node positive. By Millman’s theorem, the node voltage is?

  • A2.5 V
  • B5 V
  • C7.5 V
  • D15 V
Report an error
Correct Answer: C. 7.5 V
Explanation: V=(10/5+5/5)/(1/5+1/5)=3/0.4=7.5 V.
Reference: Standard network theory: Millman theorem numerical
Question 1628
Network TheoryPower Factor Correction

Improving a lagging load power factor by connecting a shunt capacitor primarily reduces the source?

  • AReactive current component
  • BReal power demanded by the load to zero
  • CSupply frequency
  • DLoad resistance to zero
Report an error
Correct Answer: A. Reactive current component
Explanation: The capacitor supplies leading reactive current locally, reducing the lagging reactive current drawn from the source while the load real-power requirement is essentially unchanged.
Reference: Standard network theory: power factor correction
Question 1629
Network TheoryPower Factor Correction

A 1 kW load operates at 0.8 lagging power factor. The reactive power is approximately 0.75 kVAR. To correct the power factor ideally to unity, the shunt capacitor bank should supply approximately?

  • A0.25 kVAR leading
  • B0.5 kVAR leading
  • C0.75 kVAR leading
  • D1.25 kVAR leading
Report an error
Correct Answer: C. 0.75 kVAR leading
Explanation: Unity power factor requires cancellation of the load's lagging reactive power, so the capacitor should provide about 0.75 kVAR leading.
Reference: Standard network theory: reactive compensation
Question 1632
Network TheoryNodal Analysis

In modified nodal analysis, an ideal voltage source connected between two non-reference nodes is commonly handled by introducing?

  • AAn additional source-current unknown and a voltage constraint equation
  • BAn open circuit in every case
  • CA short circuit in every case
  • DOnly a mesh-current equation with no node voltages
Report an error
Correct Answer: A. An additional source-current unknown and a voltage constraint equation
Explanation: Modified nodal analysis augments the node-voltage equations with an unknown current through the voltage source and an equation enforcing the source voltage.
Reference: Standard network theory: modified nodal analysis
Question 1633
Network TheoryNodal Analysis

A supernode is formed in nodal analysis when an ideal voltage source is connected between?

  • ATwo non-reference nodes
  • BA node and a resistor only
  • CTwo current sources in series
  • DTwo reference nodes only
Report an error
Correct Answer: A. Two non-reference nodes
Explanation: A voltage source between two unknown-voltage nodes prevents direct branch-current expression by conductance, so the two nodes are treated together as a supernode.
Reference: Standard network theory: supernode
Question 1635
Network TheoryMesh Analysis

A supermesh is used in mesh analysis when an ideal current source lies in a branch common to?

  • ATwo adjacent meshes
  • BA mesh and the reference node only
  • CTwo voltage sources in parallel
  • DTwo resistors in series only
Report an error
Correct Answer: A. Two adjacent meshes
Explanation: A current source shared by adjacent meshes prevents writing an ordinary KVL equation through that branch, so the surrounding meshes are combined into a supermesh.
Reference: Standard network theory: supermesh
Question 1637
Network TheoryNetwork Functions

For a linear network, the driving-point impedance at a port is defined as?

  • AVoltage at the port divided by current entering the same port
  • BCurrent at one port divided by voltage at another port
  • COutput power divided by input voltage
  • DVoltage multiplied by current
Report an error
Correct Answer: A. Voltage at the port divided by current entering the same port
Explanation: A driving-point impedance relates voltage and current at the same pair of terminals: Z(s)=V(s)/I(s).
Reference: Standard network theory: driving-point impedance
Question 1638
Network TheoryNetwork Functions

A transfer impedance network function is generally defined as?

  • AOutput voltage divided by input current
  • BInput voltage divided by input current at the same port only
  • COutput current divided by output voltage
  • DInput power divided by output power
Report an error
Correct Answer: A. Output voltage divided by input current
Explanation: Transfer impedance, or transimpedance, relates a response voltage at one location to an excitation current at another: Zt(s)=Vout(s)/Iin(s).
Reference: Standard network theory: transfer impedance
Question 1639
Network TheoryNetwork Functions

A transfer admittance is generally expressed as?

  • AOutput current divided by input voltage
  • BOutput voltage divided by input current
  • CInput voltage divided by input current
  • DOutput voltage divided by output current
Report an error
Correct Answer: A. Output current divided by input voltage
Explanation: Transfer admittance relates response current to excitation voltage, typically Yt(s)=Iout(s)/Vin(s).
Reference: Standard network theory: transfer admittance
Question 1640
Network TheoryNetwork Synthesis

For a physically realizable passive driving-point impedance, a necessary network-synthesis property is that the function be?

  • APositive real
  • BPurely negative real at all frequencies
  • CAn arbitrary non-rational function
  • DUnstable by definition
Report an error
Correct Answer: A. Positive real
Explanation: Driving-point immittance functions of passive RLC networks must satisfy positive-real conditions, including nonnegative real part in the right-half-plane where defined.
Reference: Standard network theory: positive-real functions
Question 1641
Network TheoryNetwork Synthesis

A real-rational function F(s) is called positive real if, among other requirements, Re[F(s)] is?

  • ANonnegative for Re(s)>0
  • BAlways negative for Re(s)>0
  • CZero for every complex s
  • DInfinite on the entire j-omega axis
Report an error
Correct Answer: A. Nonnegative for Re(s)>0
Explanation: One defining condition of a positive-real function is Re[F(s)]>=0 in the open right-half s-plane, together with appropriate real-rational symmetry conditions.
Reference: Standard network theory: positive-real condition
Question 1642
Network TheoryNetwork Synthesis

In a lossless LC driving-point reactance function, poles and zeros on the j-omega axis characteristically?

  • AInterlace
  • BAlways coincide
  • COccur only at positive real s
  • DHave no ordering relationship
Report an error
Correct Answer: A. Interlace
Explanation: For realizable LC reactance functions, simple poles and zeros lie on the imaginary axis and alternate, or interlace, with frequency.
Reference: Standard network theory: reactance functions
Question 1643
Network TheoryNetwork Synthesis

Foster’s first form for an LC driving-point impedance is obtained from a partial-fraction expansion of?

  • AThe impedance function Z(s)
  • BOnly the time-domain current
  • CThe incidence matrix
  • DThe nodal determinant only
Report an error
Correct Answer: A. The impedance function Z(s)
Explanation: Foster-I impedance realization follows directly from expanding Z(s) into partial fractions, with terms represented by simple reactive sections.
Reference: Standard network theory: Foster realization
Question 1644
Network TheoryNetwork Synthesis

Cauer network synthesis is based primarily on?

  • AContinued-fraction expansion
  • BFourier-series expansion
  • CTaylor expansion around infinity only
  • DMatrix inversion without a network function
Report an error
Correct Answer: A. Continued-fraction expansion
Explanation: Cauer forms are ladder realizations derived by successive continued-fraction expansion of a driving-point impedance or admittance.
Reference: Standard network theory: Cauer realization
Question 1650
Network TheoryTwo-Port Networks

The h-parameter h11 of a two-port is an input impedance measured with?

  • AOutput port short-circuited
  • BOutput port open-circuited
  • CInput port open-circuited
  • DBoth ports disconnected
Report an error
Correct Answer: A. Output port short-circuited
Explanation: From V1=h11 I1+h12 V2, setting V2=0 corresponds to an output short circuit, so h11=V1/I1 under that condition.
Reference: Standard network theory: h-parameters
Question 1651
Network TheoryTwo-Port Networks

The h-parameter h22 is an output admittance measured with?

  • AInput port open-circuited
  • BInput port short-circuited
  • COutput port open-circuited
  • DBoth port currents zero
Report an error
Correct Answer: A. Input port open-circuited
Explanation: From I2=h21 I1+h22 V2, setting I1=0 means the input port is open, so h22=I2/V2 under that condition.
Reference: Standard network theory: h-parameters
Question 1674
Network TheoryLaplace Transform

The Laplace transform of t for t>=0 is?

  • A1/s
  • B1/s^2
  • Cs
  • Ds^2
Report an error
Correct Answer: B. 1/s^2
Explanation: Using L{t^n}=n!/s^(n+1), for n=1 the transform is 1/s^2.
Reference: Standard network theory: transform of ramp
Question 1678
Network TheoryNetwork Functions

A stable causal rational network function requires all natural-response poles to lie where in the s-plane?

  • AOpen right-half plane
  • BOpen left-half plane
  • COnly at the origin
  • DAnywhere on the real axis
Report an error
Correct Answer: B. Open left-half plane
Explanation: For asymptotic stability of a causal continuous-time rational network, natural modes must decay, requiring poles in the open left-half plane.
Reference: Standard network theory: stability and poles
Question 1684
Network TheoryTwo-Port Networks

A transmission line section represented by ABCD parameters has A=2, B=3 ohm, C=1 siemens and D=2. Is it reciprocal?

  • AYes, because AD-BC=1
  • BNo, because AD-BC=7
  • CYes, because A=D
  • DNo, because B is not equal to C
Report an error
Correct Answer: A. Yes, because AD-BC=1
Explanation: For reciprocity, AD-BC must equal 1. Here 2×2-3×1=1, so the network satisfies the reciprocity condition.
Reference: Standard network theory: ABCD reciprocity numerical
Question 1685
Network TheoryTwo-Port Networks

When two two-port networks are connected in parallel at both ports, which parameter matrices are especially convenient to add directly?

  • Az-parameters
  • By-parameters
  • CABCD parameters
  • Dh-parameters only
Report an error
Correct Answer: B. y-parameters
Explanation: For parallel-connected two-ports, corresponding port voltages are common and currents add, making admittance or y-parameters convenient.
Reference: Standard network theory: parallel two-port connection
Question 1686
Network TheoryTwo-Port Networks

When two two-port networks are connected in series at both ports, which parameter matrices are especially convenient to add directly?

  • Az-parameters
  • By-parameters
  • CABCD parameters
  • DS-parameters only
Report an error
Correct Answer: A. z-parameters
Explanation: In a series-series interconnection, port currents are common and voltages add, so impedance or z-parameter matrices add directly.
Reference: Standard network theory: series two-port connection
Question 1687
Network TheoryTwo-Port Networks

For two cascaded two-port networks, which representation is normally the most convenient because the overall matrix is obtained by ordered multiplication?

  • Az-parameters
  • By-parameters
  • CABCD parameters
  • Dg-parameters
Report an error
Correct Answer: C. ABCD parameters
Explanation: Transmission or ABCD matrices multiply directly in cascade order, which makes them convenient for cascaded networks.
Reference: Standard network theory: cascaded two-port representation
Question 1691
Network TheoryCoupled Circuits

If the dot convention shows current entering the dotted terminal of coil 1 and the mutually induced voltage of coil 2 is referenced positive at its dotted terminal, the mutual-voltage term is taken as?

  • A+M di1/dt
  • B-M di1/dt
  • CZero for all coupling
  • DM/i1
Report an error
Correct Answer: A. +M di1/dt
Explanation: With the stated dot-reference convention, current entering a dotted terminal induces a voltage positive at the dotted terminal of the other coil, giving a positive mutual term.
Reference: Standard network theory: dot convention
Question 1694
Network TheoryNetwork Functions

A network function H(s)=(s+3)/(s^2+5s+6) has poles at?

  • A-1 and -6
  • B-2 and -3
  • C+2 and +3
  • D-3 only
Report an error
Correct Answer: B. -2 and -3
Explanation: The denominator factors as (s+2)(s+3), so the poles are at s=-2 and s=-3.
Reference: Standard network theory: pole calculation
Question 1696
Network TheoryNetwork Functions

A rational network function is strictly proper when?

  • ADegree of numerator is less than degree of denominator
  • BDegree of numerator equals degree of denominator
  • CDegree of numerator is greater than degree of denominator
  • DIts denominator is a constant
Report an error
Correct Answer: A. Degree of numerator is less than degree of denominator
Explanation: A strictly proper rational function has numerator degree lower than denominator degree, so its magnitude tends to zero as |s| tends to infinity.
Reference: Standard network theory: proper network functions
Question 1698
Network TheoryNetwork Functions

The impulse response of a causal LTI network is obtained from its transfer function H(s) by?

  • ATaking the inverse Laplace transform of H(s)
  • BDifferentiating H(s) only with respect to resistance
  • CSetting s=0 only
  • DTaking the square of H(s)
Report an error
Correct Answer: A. Taking the inverse Laplace transform of H(s)
Explanation: For zero initial conditions, the causal impulse response h(t) is the inverse Laplace transform of H(s).
Reference: Standard network theory: impulse response
Question 1699
Network TheoryNetwork Functions

If H(s)=1/(s+4), the causal impulse response is?

  • Ae^(-4t)u(t)
  • B4e^(-t)u(t)
  • C1-e^(-4t)
  • Ddelta(t-4)
Report an error
Correct Answer: A. e^(-4t)u(t)
Explanation: The inverse Laplace transform of 1/(s+a) is e^(-at)u(t), so h(t)=e^(-4t)u(t).
Reference: Standard network theory: impulse response numerical