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JTO MCQs

Practice JTO-oriented Electronics & Telecommunication Engineering MCQs with answers and explanations for technical exam preparation. Questions are arranged in pages of up to 100.

Question 1502
Analog ElectronicsDifferential Amplifiers

Using a current-mirror active load in a differential amplifier can convert the differential collector currents into?

  • AA useful single-ended output current
  • BA fixed DC supply voltage
  • CA digital clock only
  • DZero output current for every input
Report an error
Correct Answer: A. A useful single-ended output current
Explanation: The mirror redirects one branch-current variation and combines it with the other branch, producing a single-ended output with enhanced gain.
Reference: Standard analog electronics: active-load differential amplifier
Question 1503
Analog ElectronicsCurrent Mirrors

In a basic BJT current mirror, finite transistor beta causes the output current to differ from the ideal reference mainly because?

  • AThe reference branch must also supply base currents
  • BCollector resistors become inductors
  • CThe Early voltage becomes zero
  • DBoth transistors enter breakdown automatically
Report an error
Correct Answer: A. The reference branch must also supply base currents
Explanation: The reference current supplies the diode-connected transistor collector current plus the base currents of the mirror transistors, producing finite-beta error.
Reference: Standard analog electronics: current-mirror error
Question 1504
Analog ElectronicsCurrent Mirrors

A Wilson current mirror is commonly preferred over a simple two-transistor mirror because it offers?

  • AImproved current accuracy and higher output resistance
  • BZero transistor count
  • CNo need for a reference current
  • DOnly AC operation
Report an error
Correct Answer: A. Improved current accuracy and higher output resistance
Explanation: The Wilson topology uses feedback to reduce base-current-related error and generally raises output resistance compared with a simple mirror.
Reference: Standard analog electronics: Wilson current mirror
Question 1505
Analog ElectronicsCurrent Mirrors

A Widlar current source is especially useful in integrated circuits for generating?

  • ASmall currents using practical resistor values
  • BVery large RF power directly
  • COnly alternating current
  • DA precisely zero output current
Report an error
Correct Answer: A. Small currents using practical resistor values
Explanation: Emitter degeneration in the Widlar arrangement allows currents much smaller than the reference current without requiring impractically large on-chip resistors.
Reference: Standard analog electronics: Widlar current source
Question 1506
Analog ElectronicsDifferential Amplifiers

For a long-tailed differential pair, increasing the small-signal resistance of the tail-current source primarily reduces?

  • ACommon-mode gain
  • BDifferential input resistance to zero
  • CDifferential gain to zero
  • DSupply voltage
Report an error
Correct Answer: A. Common-mode gain
Explanation: A high tail resistance makes total current less sensitive to common-mode voltage changes, reducing common-mode gain and improving CMRR.
Reference: Standard analog electronics: common-mode rejection
Question 1508
Analog ElectronicsOperational Amplifiers

An op-amp has a unity-gain frequency of 10 MHz and is used at a noise gain of 20. Under a single-dominant-pole approximation, the closed-loop bandwidth is approximately?

  • A50 kHz
  • B500 kHz
  • C2 MHz
  • D20 MHz
Report an error
Correct Answer: B. 500 kHz
Explanation: Closed-loop bandwidth is approximately unity-gain frequency divided by noise gain: 10 MHz/20=500 kHz.
Reference: Standard analog electronics: gain-bandwidth numerical
Question 1510
Analog ElectronicsOperational Amplifiers

An op-amp’s input common-mode voltage range specifies the range over which?

  • ABoth input voltages may move together while the input stage operates properly
  • BThe output must always equal zero
  • CThe supply current becomes infinite
  • DThe feedback factor is exactly one
Report an error
Correct Answer: A. Both input voltages may move together while the input stage operates properly
Explanation: The common-mode input range defines allowable common movement of the input terminals while maintaining proper input-stage operation.
Reference: Standard analog electronics: input common-mode range
Question 1511
Analog ElectronicsOperational Amplifiers

Output voltage swing of a practical op-amp is limited mainly by?

  • AIts output stage and supply rails
  • BOnly the input resistor value
  • COnly the feedback capacitor
  • DThe ideal virtual-short condition
Report an error
Correct Answer: A. Its output stage and supply rails
Explanation: A real output stage cannot generally drive exactly to or beyond its supply rails, and load current can further restrict available output swing.
Reference: Standard analog electronics: output swing
Question 1512
Analog ElectronicsOperational Amplifiers

Rail-to-rail input/output op-amps are designed primarily to?

  • AOperate with signal ranges closer to the supply rails
  • BProvide infinite bandwidth
  • CEliminate all offset voltage
  • DOperate without power supplies
Report an error
Correct Answer: A. Operate with signal ranges closer to the supply rails
Explanation: Rail-to-rail architectures extend input common-mode range and/or output swing close to the supply rails, useful at low supply voltages.
Reference: Standard analog electronics: rail-to-rail op-amps
Question 1513
Analog ElectronicsOperational Amplifiers

The power-supply rejection ratio (PSRR) of an op-amp indicates its ability to reject?

  • AChanges or noise on the supply voltages
  • BDifferential input signals
  • CAll output load current
  • DFeedback resistor tolerance only
Report an error
Correct Answer: A. Changes or noise on the supply voltages
Explanation: High PSRR means variations on the power rails cause relatively little input-referred or output error.
Reference: Standard analog electronics: PSRR
Question 1514
Analog ElectronicsDifferential Amplifiers

In a BJT differential pair with an ideal tail current of 1 mA and zero differential input, the quiescent collector current of each matched transistor is approximately?

  • A0.25 mA
  • B0.5 mA
  • C1 mA
  • D2 mA
Report an error
Correct Answer: B. 0.5 mA
Explanation: With zero differential input, an ideal matched pair shares the 1 mA tail current equally, so each transistor carries about 0.5 mA.
Reference: Standard analog electronics: differential pair bias
Question 1516
Analog ElectronicsOperational Amplifier Applications

A logarithmic amplifier commonly uses a diode or transistor junction in its feedback path because the junction has an approximately?

  • AExponential current-voltage characteristic
  • BPerfectly linear resistance
  • CInfinite breakdown voltage
  • DConstant current independent of voltage
Report an error
Correct Answer: A. Exponential current-voltage characteristic
Explanation: The exponential junction law allows an op-amp feedback circuit to produce an output proportional to the logarithm of input current or voltage.
Reference: Standard analog electronics: logarithmic amplifier
Question 1517
Analog ElectronicsOperational Amplifier Applications

An antilog amplifier produces an output related approximately to?

  • AThe exponential of its input
  • BThe derivative of its input only
  • CThe average of two supplies
  • DA fixed digital code
Report an error
Correct Answer: A. The exponential of its input
Explanation: By placing an exponential junction in the input path and using linear feedback, the circuit can generate an exponential, or antilogarithmic, transfer.
Reference: Standard analog electronics: antilog amplifier
Question 1518
Analog ElectronicsAnalog Signal Processing

A sample-and-hold circuit uses a capacitor primarily to?

  • AStore the sampled analog voltage between sampling instants
  • BGenerate a clock without any switch
  • CIncrease transistor beta
  • DRectify the input continuously
Report an error
Correct Answer: A. Store the sampled analog voltage between sampling instants
Explanation: During sample mode the capacitor charges to the input level; during hold mode it retains that voltage as closely as practical.
Reference: Standard analog electronics: sample-and-hold
Question 1519
Analog ElectronicsAnalog Signal Processing

In a sample-and-hold circuit, droop rate refers to?

  • AThe gradual change of held output voltage with time
  • BThe sampling frequency itself
  • CThe instantaneous input resistance only
  • DThe op-amp open-loop gain
Report an error
Correct Answer: A. The gradual change of held output voltage with time
Explanation: Leakage currents and finite storage cause the held capacitor voltage to change slowly; this rate is called droop.
Reference: Standard analog electronics: sample-and-hold droop
Question 1520
Analog ElectronicsAnalog Signal Processing

An analog multiplier whose output is proportional to Vx times Vy can be used as a frequency doubler by applying the same sinusoid to both inputs because sin^2(theta) contains?

  • AA DC term and a component at twice the input frequency
  • BOnly the original frequency
  • COnly a component at half the frequency
  • DNo AC component
Report an error
Correct Answer: A. A DC term and a component at twice the input frequency
Explanation: sin²(theta)=[1-cos(2theta)]/2, so squaring a sinusoid produces a DC term and a second-harmonic component.
Reference: Standard analog electronics: analog multiplier
Question 1521
Analog ElectronicsOscillators & PLL

A voltage-controlled oscillator (VCO) is an oscillator whose output frequency is primarily controlled by?

  • AAn applied control voltage
  • BOnly ambient temperature
  • CThe load resistance alone
  • DA fixed diode current with no control input
Report an error
Correct Answer: A. An applied control voltage
Explanation: A VCO converts a control voltage into a corresponding change in oscillation frequency and is widely used in modulation and PLL systems.
Reference: Standard analog electronics: voltage-controlled oscillator
Question 1522
Analog ElectronicsOscillators & PLL

In a phase-locked loop, the phase detector produces a signal related to?

  • AThe phase difference between reference and feedback signals
  • BOnly the output amplitude
  • CThe transistor collector current only
  • DThe power-supply voltage
Report an error
Correct Answer: A. The phase difference between reference and feedback signals
Explanation: The phase detector compares reference and feedback phases; after loop filtering, its error signal controls the VCO to establish lock.
Reference: Standard analog electronics: phase-locked loop
Question 1524
Analog ElectronicsOperational Amplifier Applications

A transimpedance amplifier is designed primarily to convert?

  • AInput current into output voltage
  • BInput voltage into output frequency
  • CResistance into inductance
  • DDigital code into current only
Report an error
Correct Answer: A. Input current into output voltage
Explanation: With current applied to the inverting summing node, the feedback resistor produces an output voltage proportional to input current.
Reference: Standard analog electronics: transimpedance amplifier
Question 1525
Analog ElectronicsActive Filters

In a first-order passive RC low-pass network, the magnitude of the transfer function at the cutoff frequency is approximately what fraction of its low-frequency value?

  • A0.5
  • B0.707
  • C1.0
  • D1.414
Report an error
Correct Answer: B. 0.707
Explanation: At the cutoff frequency of a first-order RC network, the magnitude is 1/sqrt(2), approximately 0.707 of the passband value.
Reference: Standard analog electronics: first-order filter cutoff
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Question 1526
Analog ElectronicsActive Filters

A first-order high-pass filter with cutoff frequency 1 kHz is operated at 100 Hz, one decade below cutoff. Its asymptotic gain relative to the passband is approximately?

  • A-3 dB
  • B-10 dB
  • C-20 dB
  • D-40 dB
Report an error
Correct Answer: C. -20 dB
Explanation: A first-order high-pass response rises at about 20 dB/decade below cutoff, so one decade below cutoff the asymptotic attenuation is about 20 dB.
Reference: Standard analog electronics: high-pass filter response
Question 1529
Analog ElectronicsActive Filters

A notch filter is designed primarily to?

  • AStrongly attenuate a narrow band around a selected frequency
  • BPass only DC and reject all AC
  • CAmplify every frequency equally
  • DGenerate a sinusoidal signal without input
Report an error
Correct Answer: A. Strongly attenuate a narrow band around a selected frequency
Explanation: A notch, or band-stop, filter produces strong rejection around a chosen frequency while passing frequencies on either side.
Reference: Standard analog electronics: notch filter
Question 1530
Analog ElectronicsOscillators & PLL

In a phase-locked loop, the loop filter is placed mainly between the phase detector and VCO to?

  • ASmooth the detector output and shape loop dynamics
  • BGenerate the reference frequency by itself
  • CRectify the VCO output for power conversion
  • DEliminate the need for feedback
Report an error
Correct Answer: A. Smooth the detector output and shape loop dynamics
Explanation: The loop filter removes unwanted high-frequency detector components and determines important loop bandwidth and dynamic characteristics.
Reference: Standard analog electronics: PLL loop filter
Question 1531
Analog ElectronicsOscillators & PLL

A PLL is said to be locked when the VCO output and reference have?

  • AA constant phase relationship and the required frequency relationship
  • BRandomly changing frequencies
  • CExactly zero amplitudes
  • DNo feedback connection
Report an error
Correct Answer: A. A constant phase relationship and the required frequency relationship
Explanation: In lock, feedback maintains the required frequency relationship and the phase error settles to a constant value appropriate to the loop.
Reference: Standard analog electronics: PLL lock
Question 1533
Analog ElectronicsOscillators & PLL

The capture range of a PLL refers to the range of input frequencies over which an initially unlocked loop can?

  • AAcquire lock
  • BMaintain transistor saturation only
  • CProduce zero output
  • DOperate without a VCO
Report an error
Correct Answer: A. Acquire lock
Explanation: Capture range describes the frequency range from which an unlocked loop can acquire synchronization with the input.
Reference: Standard analog electronics: PLL capture range
Question 1534
Analog ElectronicsOscillators & PLL

The lock or hold-in range of a PLL generally describes the range over which an already locked loop can?

  • ARemain locked while input frequency varies
  • BStart oscillating with no reference
  • CSuppress all supply current
  • DAct as a rectifier
Report an error
Correct Answer: A. Remain locked while input frequency varies
Explanation: Once lock is established, the loop can track input-frequency variation over its lock or hold-in range.
Reference: Standard analog electronics: PLL lock range
Question 1536
Analog ElectronicsComparators & Waveform Generators

A zero-crossing detector is essentially a comparator whose reference voltage is?

  • A0 V
  • B1 V
  • CEqual to the positive supply
  • DAlways equal to the output
Report an error
Correct Answer: A. 0 V
Explanation: A zero-crossing detector compares the input with a zero-volt reference and switches output polarity when the input crosses zero.
Reference: Standard analog electronics: zero-crossing detector
Question 1537
Analog ElectronicsComparators & Waveform Generators

An op-amp relaxation oscillator typically generates a square wave by combining a Schmitt-trigger action with?

  • ARC charging and discharging
  • BA transformer rectifier only
  • CA current mirror with no capacitor
  • DA crystal operated only at series resonance
Report an error
Correct Answer: A. RC charging and discharging
Explanation: The capacitor repeatedly charges and discharges between hysteresis thresholds, causing the comparator output to switch and sustain oscillation.
Reference: Standard analog electronics: relaxation oscillator
Question 1538
Analog ElectronicsComparators & Waveform Generators

In a basic op-amp astable relaxation oscillator, increasing the timing resistance while all other parameters remain unchanged generally causes the oscillation frequency to?

  • AIncrease
  • BDecrease
  • CRemain exactly unchanged
  • DBecome infinite
Report an error
Correct Answer: B. Decrease
Explanation: Increasing timing resistance increases the RC charging/discharging time, so the oscillation period grows and frequency decreases.
Reference: Standard analog electronics: relaxation oscillator timing
Question 1541
Analog ElectronicsActive Filters

Compared with a Butterworth filter of the same order, a Chebyshev Type I filter generally provides?

  • AA sharper transition at the cost of passband ripple
  • BNo passband ripple and slower transition in every case
  • CZero phase shift
  • DNo frequency selectivity
Report an error
Correct Answer: A. A sharper transition at the cost of passband ripple
Explanation: Chebyshev Type I uses equal-ripple passband behavior to obtain a steeper transition than a comparable Butterworth design.
Reference: Standard analog electronics: Chebyshev filter
Question 1542
Analog ElectronicsActive Filters

A Bessel filter is often selected when the main requirement is good preservation of waveform shape because it emphasizes?

  • AApproximately linear phase and nearly constant group delay in the passband
  • BMaximum passband ripple
  • CInfinite stopband attenuation at cutoff
  • DNegative resistance
Report an error
Correct Answer: A. Approximately linear phase and nearly constant group delay in the passband
Explanation: Bessel responses are valued for nearly constant group delay and good transient behavior, helping preserve pulse and waveform shape.
Reference: Standard analog electronics: Bessel filter
Question 1544
Analog ElectronicsPower Amplifiers

For a transistor dissipating 3 W with total junction-to-ambient thermal resistance of 20 degrees C/W at an ambient temperature of 30 degrees C, the estimated junction temperature is?

  • A50 degrees C
  • B60 degrees C
  • C90 degrees C
  • D110 degrees C
Report an error
Correct Answer: C. 90 degrees C
Explanation: The temperature rise is P×theta=3×20=60 degrees C. Adding 30 degrees C ambient gives an estimated junction temperature of 90 degrees C.
Reference: Standard analog electronics: thermal calculation
Question 1545
Analog ElectronicsWaveform Generators

A monostable multivibrator has how many stable states?

  • AZero
  • BOne
  • CTwo
  • DFour
Report an error
Correct Answer: B. One
Explanation: A monostable circuit has one stable state and one temporary quasi-stable state entered after triggering.
Reference: Standard analog electronics: monostable multivibrator
Question 1546
Analog ElectronicsWaveform Generators

An astable multivibrator is characterized by?

  • ANo stable state and continuous self-oscillation
  • BExactly one stable state
  • CTwo stable states with no automatic transitions
  • DA fixed DC output only
Report an error
Correct Answer: A. No stable state and continuous self-oscillation
Explanation: An astable multivibrator has no stable state and continuously alternates between two states, generating a periodic waveform.
Reference: Standard analog electronics: astable multivibrator
Question 1547
Analog ElectronicsWaveform Generators

A bistable multivibrator has?

  • ANo stable states
  • BOne stable state
  • CTwo stable states
  • DThree stable states
Report an error
Correct Answer: C. Two stable states
Explanation: A bistable circuit can remain indefinitely in either of two stable states until an external trigger causes a transition.
Reference: Standard analog electronics: bistable multivibrator
Question 1549
Analog ElectronicsPower Amplifiers

A class-AB output stage is biased so that each output device conducts for?

  • ALess than 180 degrees
  • BExactly 180 degrees
  • CMore than 180 degrees but less than 360 degrees
  • DExactly 360 degrees in every design
Report an error
Correct Answer: C. More than 180 degrees but less than 360 degrees
Explanation: Class-AB operation lies between class A and class B; each device conducts for more than half a cycle but less than the full cycle.
Reference: Standard analog electronics: class-AB conduction angle
Question 1550
Analog ElectronicsOperational Amplifier Applications

An ideal peak detector using an op-amp, diode and capacitor is intended to hold approximately?

  • AThe maximum value reached by the input waveform
  • BThe RMS value of every waveform automatically
  • COnly the zero crossing
  • DThe input frequency as a voltage
Report an error
Correct Answer: A. The maximum value reached by the input waveform
Explanation: The diode-capacitor feedback arrangement charges the storage capacitor to the input peak and ideally holds that level between larger peaks.
Reference: Standard analog electronics: peak detector
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Question 1551
Analog ElectronicsOperational Amplifier Applications

In a practical peak detector, a high input-resistance buffer after the hold capacitor is useful mainly to?

  • AReduce discharge of the stored voltage by the load
  • BIncrease diode forward drop
  • CForce the capacitor to discharge immediately
  • DCreate positive feedback oscillation
Report an error
Correct Answer: A. Reduce discharge of the stored voltage by the load
Explanation: A buffer isolates the storage capacitor from the load, reducing loading and helping the held peak voltage decay more slowly.
Reference: Standard analog electronics: buffered peak detector
Question 1552
Analog ElectronicsWave-Shaping Circuits

A clamper circuit primarily changes which property of a waveform while ideally preserving its peak-to-peak value?

  • AIts DC level
  • BIts frequency
  • CIts harmonic order only
  • DIts source resistance only
Report an error
Correct Answer: A. Its DC level
Explanation: A clamper shifts the entire waveform upward or downward by adding a DC component while ideally retaining the original peak-to-peak amplitude.
Reference: Standard analog electronics: clamper circuit
Question 1554
Analog ElectronicsWave-Shaping Circuits

A diode limiter is commonly used in analog circuits to?

  • ARestrict signal amplitude beyond selected levels
  • BIncrease all signal amplitudes linearly
  • CGenerate a constant current mirror
  • DProvide galvanic isolation
Report an error
Correct Answer: A. Restrict signal amplitude beyond selected levels
Explanation: Limiter or clipper circuits use diode conduction to constrain waveform excursions above or below chosen threshold levels.
Reference: Standard analog electronics: diode limiter
Question 1555
Analog ElectronicsOperational Amplifier Applications

A full-wave precision rectifier is especially useful when the input amplitude is?

  • AComparable to or smaller than an ordinary diode forward drop
  • BAlways hundreds of volts
  • CExactly zero only
  • DA digital logic level only
Report an error
Correct Answer: A. Comparable to or smaller than an ordinary diode forward drop
Explanation: Op-amp feedback compensates much of the diode threshold error, allowing accurate rectification of low-level analog signals.
Reference: Standard analog electronics: full-wave precision rectifier
Question 1558
Analog ElectronicsAnalog Signal Processing

The RMS-to-DC converter is designed primarily to produce a DC output proportional to?

  • AThe RMS value of the input signal
  • BOnly the positive peak
  • COnly the average frequency
  • DThe input phase angle
Report an error
Correct Answer: A. The RMS value of the input signal
Explanation: An RMS-to-DC converter performs the nonlinear operations needed to represent the effective or heating value of an AC waveform as a DC level.
Reference: Standard analog electronics: RMS-to-DC conversion
Question 1560
Analog ElectronicsAnalog Signal Processing

In an analog sample-and-hold circuit, acquisition time is the time required after entering sample mode for the held voltage to?

  • ASettle sufficiently close to the input value
  • BDecay completely to zero
  • CReach the supply voltage regardless of input
  • DComplete one oscillation cycle
Report an error
Correct Answer: A. Settle sufficiently close to the input value
Explanation: Acquisition time measures how long the circuit needs to charge its hold capacitor and settle to the new sampled input within a specified error.
Reference: Standard analog electronics: sample-and-hold acquisition time
Question 1562
Analog ElectronicsSwitched-Capacitor Circuits

A switched-capacitor circuit transfers charge Q=C(V1-V2) each clock cycle. Its average transferred current at clock frequency f is approximately?

  • AC(V1-V2)/f
  • BCf(V1-V2)
  • Cf/[C(V1-V2)]
  • DC/f only
Report an error
Correct Answer: B. Cf(V1-V2)
Explanation: Average current equals charge per cycle multiplied by cycles per second: Iavg=Qf=Cf(V1-V2).
Reference: Standard analog electronics: switched-capacitor charge transfer
Question 1564
Analog ElectronicsPrecision Amplifiers

Chopper stabilization in a precision amplifier is mainly used to reduce?

  • AInput offset and low-frequency 1/f noise
  • BHigh-frequency carrier power only
  • COutput load current
  • DSupply voltage requirement to zero
Report an error
Correct Answer: A. Input offset and low-frequency 1/f noise
Explanation: Chopper techniques modulate low-frequency signals away from the region dominated by offset and flicker noise, then demodulate them after amplification.
Reference: Standard analog electronics: chopper stabilization
Question 1565
Analog ElectronicsNoise in Analog Circuits

The noise spectral density associated with flicker noise generally becomes more significant as frequency?

  • ADecreases
  • BIncreases without limit
  • CRemains exactly constant at all frequencies
  • DEquals the supply frequency only
Report an error
Correct Answer: A. Decreases
Explanation: Flicker noise is commonly called 1/f noise because its spectral density increases toward lower frequencies.
Reference: Standard analog electronics: flicker noise
Question 1569
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 1572
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 1573
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
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Question 1580
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 1582
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 1583
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 1584
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 1585
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 1595
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 1596
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 1599
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 1600
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
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