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Analog Electronics MCQs

Practice Analog Electronics MCQs from fundamental concepts through intermediate, advanced and application-oriented questions. Each page contains up to 100 questions with answers and explanations where available.

Question 102
Analog ElectronicsHigh-Frequency Amplifiers

A cascode amplifier combines a common-emitter or common-source input device with a common-base or common-gate device mainly to obtain?

  • AHigh gain with improved high-frequency response
  • BZero input impedance
  • COnly unity voltage gain
  • DFull-wave rectification
Report an error
Correct Answer: A. High gain with improved high-frequency response
Explanation: The cascode suppresses large voltage variation at the input device's output node, reducing Miller effect while retaining useful gain.
Reference: Standard analog electronics: cascode amplifier
Question 111
Analog ElectronicsSmall-Signal Amplifiers

An unbypassed emitter resistor in a common-emitter amplifier generally causes the voltage gain magnitude to?

  • AIncrease without limit
  • BDecrease while improving linearity
  • CRemain exactly unchanged
  • DBecome exactly unity in every case
Report an error
Correct Answer: B. Decrease while improving linearity
Explanation: Emitter degeneration introduces local negative feedback, reducing gain but improving linearity and bias stability.
Reference: Standard analog electronics: emitter degeneration
Question 112
Analog ElectronicsSmall-Signal Amplifiers

A bypass capacitor placed across an emitter resistor is intended mainly to?

  • AReduce AC emitter degeneration over its effective frequency range
  • BIncrease DC emitter resistance
  • CBlock all collector current
  • DCreate positive DC feedback
Report an error
Correct Answer: A. Reduce AC emitter degeneration over its effective frequency range
Explanation: The capacitor provides a low-impedance AC path around the emitter resistor while leaving the resistor available for DC bias stabilization.
Reference: Standard analog electronics: emitter bypass capacitor
Question 113
Analog ElectronicsMultistage Amplifiers

In a multistage RC-coupled amplifier, the coupling capacitor between stages primarily?

  • APasses AC while blocking the DC bias of one stage from disturbing the next
  • BPasses only DC
  • CProvides transistor heat sinking
  • DCreates a current mirror
Report an error
Correct Answer: A. Passes AC while blocking the DC bias of one stage from disturbing the next
Explanation: RC coupling transfers the signal while isolating the DC operating points of adjacent amplifier stages.
Reference: Standard analog electronics: RC coupling
Question 116
Analog ElectronicsOperational Amplifier Applications

A practical op-amp differentiator is commonly bandwidth-limited with additional resistive/capacitive components mainly because an ideal differentiator strongly amplifies?

  • AHigh-frequency noise
  • BDC only
  • CPower-supply current only
  • DCommon-mode voltage only
Report an error
Correct Answer: A. High-frequency noise
Explanation: The ideal differentiator's gain rises with frequency, making it highly sensitive to high-frequency noise and stability problems; practical designs limit this gain.
Reference: Standard analog electronics: practical differentiator
Question 118
Analog ElectronicsFeedback Amplifiers

If negative feedback reduces an amplifier’s gain by a factor of 10 while approximately preserving gain-bandwidth product, its bandwidth ideally changes by roughly what factor?

  • ADecreases by 10
  • BIncreases by 10
  • CDoes not change
  • DIncreases by 100
Report an error
Correct Answer: B. Increases by 10
Explanation: Negative feedback commonly trades gain for bandwidth; under the constant gain-bandwidth approximation, a tenfold gain reduction gives about tenfold bandwidth increase.
Reference: Standard analog electronics: feedback bandwidth
Question 121
Analog ElectronicsOperational Amplifiers

In an ideal op-amp circuit operating with negative feedback in its linear region, the voltage difference V+ – V- is approximately?

  • AZero
  • BEqual to the supply voltage
  • CInfinite
  • DAlways 1 V
Report an error
Correct Answer: A. Zero
Explanation: The very large open-loop gain with negative feedback forces the two input-node voltages to be nearly equal; this is the virtual-short approximation.
Reference: Standard analog electronics: virtual short
Question 122
Analog ElectronicsOperational Amplifiers

The term virtual ground in an inverting op-amp circuit means the inverting input node is approximately at ground potential while?

  • AIt is not physically shorted to ground
  • BIt carries infinite current to ground
  • CThe op-amp supply is disconnected
  • DThe feedback path is open
Report an error
Correct Answer: A. It is not physically shorted to ground
Explanation: Negative feedback holds the inverting node near the grounded non-inverting input voltage, although there is no direct physical ground connection at that node.
Reference: Standard analog electronics: virtual ground
Question 125
Analog ElectronicsOperational Amplifier Applications

A precision rectifier using an op-amp is useful for small signals mainly because feedback can?

  • ACompensate much of the ordinary diode forward-drop error
  • BMake diode current exactly zero
  • CConvert every signal to digital form
  • DEliminate the need for a power supply
Report an error
Correct Answer: A. Compensate much of the ordinary diode forward-drop error
Explanation: Placing the diode within an op-amp feedback arrangement allows accurate rectification of signals much smaller than a normal diode's forward drop.
Reference: Standard analog electronics: precision rectifier
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Question 126
Analog ElectronicsOperational Amplifier Applications

A practical op-amp integrator often places a resistor in parallel with the feedback capacitor mainly to?

  • ALimit DC gain and reduce saturation from offsets
  • BIncrease DC gain to infinity
  • CRemove all negative feedback
  • DMake the circuit a comparator
Report an error
Correct Answer: A. Limit DC gain and reduce saturation from offsets
Explanation: The parallel resistor provides finite DC feedback, preventing tiny offsets and bias currents from integrating indefinitely and driving the output into saturation.
Reference: Standard analog electronics: practical integrator
Question 127
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 128
Analog ElectronicsDifferential Amplifiers

For a BJT differential pair at room temperature with total tail current IT, the small-signal differential transconductance from differential input voltage to single-ended collector-current change is approximately?

  • AIT/(4VT)
  • BIT/VT
  • C4IT/VT
  • DVT/IT
Report an error
Correct Answer: A. IT/(4VT)
Explanation: Each transistor carries IT/2 at balance, giving gm=IT/(2VT). For differential excitation, the single-ended collector-current change is gm(vd/2), so the effective differential transconductance is IT/(4VT).
Reference: Standard analog electronics: differential transconductance
Question 130
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 131
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 132
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 133
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 134
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 136
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 138
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 139
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 140
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 141
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 143
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 145
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 146
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 147
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 148
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 149
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 150
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
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Question 151
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 152
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
Question 153
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 155
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 158
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 159
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 160
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 162
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 163
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 165
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 166
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 167
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 170
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 172
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 173
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 174
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 175
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
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Question 176
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 178
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
Question 179
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 180
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 182
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 183
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 186
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 188
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 192
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 193
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 197
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 200
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
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