ECE131 Unit 5: Fundamentals of filters and operational amplifier - MCQ Practice | B. Tech. Biotechnology

1 $What does a band-pass filter allow to pass?$

Band-pass filter Easy

A.

Only direct current signals

B.

All frequencies equally

C.

Only frequencies below zero

D.

A specific range of frequencies

2 $Which frequencies are passed by a low-pass filter?$

Low-pass filter Easy

A.

Frequencies above the cutoff frequency

B.

Frequencies below the cutoff frequency

C.

Frequencies at the resonant frequency only

D.

Frequencies within a narrow middle band

3 $What is the main function of a high-pass filter?$

High-pass filter Easy

A.

To pass only direct current

B.

To reject every alternating signal

C.

To pass frequencies above the cutoff frequency

D.

To pass frequencies below the cutoff frequency

4 $An operational amplifier is commonly represented as a device with how many signal input terminals?$

Operational amplifier abstraction Easy

A.

Three signal input terminals

B.

Two signal input terminals

C.

Four signal input terminals

D.

One signal input terminal

5 $What is the ideal input impedance of an operational amplifier?$

Device properties of the operational amplifier Easy

A.

Equal to the load

B.

One ohm

C.

Zero

D.

Infinite

6 $What is the purpose of negative feedback in a simple op-amp amplifier circuit?$

Simple op-amp circuits Easy

A.

To remove the supply voltage

B.

To provide stable closed-loop gain

C.

To produce unlimited output voltage

D.

To eliminate the input signal

7 $In an ideal inverting op-amp circuit, what is the voltage at the inverting input when the non-inverting input is grounded?$

Virtual ground concept Easy

A.

Approximately the full output voltage

B.

Approximately

C.

Approximately the positive supply voltage

D.

Approximately the negative supply voltage

8 $What is the voltage gain of an ideal inverting amplifier with input resistance and feedback resistance ?$

Inverting op-amp Easy

A.

B.

C.

D.

9 $What is the phase relationship between the input and output of a non-inverting op-amp amplifier?$

Non-inverting op-amp Easy

A.

They differ by

B.

They are in phase

C.

Their phase difference always changes

D.

They differ by

10 $Which components are normally used in a first-order active high-pass filter?$

Active high-pass filter Easy

A.

An op-amp, a resistor, and a capacitor

B.

A transformer, a diode, and a fuse

C.

A motor, a relay, and an inductor

D.

A battery, a switch, and a lamp

11 $An active band-pass filter can be formed by combining which two filtering actions?$

Active band-pass filter Easy

A.

Band-stop and all-pass filtering

B.

High-pass and high-pass filtering

C.

Low-pass and low-pass filtering

D.

High-pass and low-pass filtering

12 $What does an active band-stop filter do?$

Active band-stop filter Easy

A.

Attenuates a selected band of frequencies

B.

Blocks all frequencies above the cutoff

C.

Blocks all frequencies below the cutoff

D.

Passes only a selected band of frequencies

13 $What is the ideal output impedance of an operational amplifier?$

Properties of operational amplifier Easy

A.

Equal to the input impedance

B.

Infinite

C.

Equal to the feedback resistance

D.

Zero

14 $What mathematical operation is performed by an op-amp summing amplifier?$

Op-amp as an adder Easy

A.

Multiplication of input signals

B.

Differentiation of input signals

C.

Comparison of input signals

D.

Addition of input signals

15 $What output does an op-amp subtractor produce?$

Op-amp as a subtractor Easy

A.

A pulse for every input cycle

B.

A constant voltage independent of input

C.

A voltage proportional to the input sum

D.

A voltage proportional to the input difference

16 $Which property of a capacitor is commonly used in op-amp RC circuits?$

Op-amp RC circuits Easy

A.

Its resistance remains infinite at all frequencies

B.

Its inductance increases with current

C.

Its reactance changes with frequency

D.

Its voltage changes without storing charge

17 $What is the output of an ideal op-amp integrator proportional to?$

Op-amp integrator Easy

A.

The time derivative of the input

B.

The time integral of the input

C.

The average supply voltage

D.

The square of the input

18 $How does an ideal op-amp differentiator respond to a constant input voltage?$

Op-amp differentiator Easy

A.

It produces a constant negative output

B.

It produces a constant positive output

C.

It produces zero output

D.

It produces a sinusoidal output

19 $What does an op-amp comparator do?$

Op-amp as a comparator Easy

A.

Adds two input voltages

B.

Stores an input voltage

C.

Compares two input voltages

D.

Converts voltage into resistance

20 $In an anti-lock braking system, an op-amp comparator can be used to compare a wheel-speed sensor signal with what?$

Application of op-amp comparator in anti-lock braking systems Easy

A.

The brake-disc diameter

B.

The tire air volume

C.

The battery capacity

D.

A reference voltage

21 $A first-order RC low-pass filter has and . What is its approximate cutoff frequency?$

Low-pass filter Medium

A.

B.

C.

D.

22 $A first-order high-pass filter has a cutoff frequency of . What is the approximate magnitude of its voltage gain at ?$

High-pass filter Medium

A.

B.

C.

D.

23 $A band-pass filter has lower and upper cutoff frequencies of and, respectively. Which input frequency lies within its passband?$

Band-pass filter Medium

A.

B.

C.

D.

24 $In the ideal op-amp abstraction with negative feedback and linear operation, which relationship is normally used to analyze the circuit?$

Operational amplifier abstraction Medium

A.

B.

C.

always

D.

always

25 $An op-amp has a slew rate of . What is the highest frequency at which it can reproduce a peak sine wave without slew-rate distortion?$

Device properties of the operational amplifier Medium

A.

B.

C.

D.

26 $A voltage follower is connected to a source and powered from suitable supply rails. Assuming an ideal op-amp, what are its output voltage and main practical benefit?$

Simple op-amp circuits Medium

A.

and voltage amplification

B.

and phase inversion

C.

and impedance buffering

D.

and voltage division

27 $In an ideal inverting amplifier, the non-inverting input is grounded and negative feedback is present. Why is the inverting input called a virtual ground?$

Virtual ground concept Medium

A.

It remains near without a ground connection

B.

It supplies the circuit ground current

C.

It has infinite voltage relative to ground

D.

It is physically shorted to ground

28 $An ideal inverting amplifier has,, and . What is the output voltage?$

Inverting op-amp Medium

A.

B.

C.

D.

29 $A non-inverting amplifier must produce from a input. If the resistor from the inverting input to ground is, what feedback resistance is required?$

Non-inverting op-amp Medium

A.

B.

C.

D.

30 $A first-order active high-pass filter has a passband gain of and a cutoff frequency of . What is its approximate gain magnitude at the cutoff frequency?$

Active high-pass filter Medium

A.

B.

C.

D.

31 $An active band-pass filter has cutoff frequencies of and . What is its approximate center frequency?$

Active band-pass filter Medium

A.

B.

C.

D.

32 $A sensor signal contains unwanted power-line interference while frequencies below and above must be retained. Which filter is most suitable?$

Active band-stop filter Medium

A.

A band-pass filter from to

B.

A band-stop filter from to

C.

A high-pass filter at

D.

A low-pass filter at

33 $An op-amp receives the same noise signal at both input terminals. Which property determines how effectively the op-amp rejects this common signal?$

Properties of operational amplifier Medium

A.

Input offset voltage

B.

Gain-bandwidth product

C.

Slew rate

D.

Common-mode rejection ratio

34 $An ideal inverting summing amplifier has two input resistors of and a feedback resistor of . If the inputs are and, what is the output?$

Op-amp as an adder Medium

A.

B.

C.

D.

35 $A differential amplifier has matched resistor ratios . If is applied to the non-inverting side and to the inverting side, what is the output?$

Op-amp as a subtractor Medium

A.

B.

C.

D.

36 $An ideal op-amp integrator has and . A constant input is applied for, starting from zero output. What is the final output?$

Op-amp integrator Medium

A.

B.

C.

D.

37 $An ideal op-amp differentiator has and . If the input increases linearly at, what is the output voltage?$

Op-amp differentiator Medium

A.

B.

C.

D.

38 $A practical op-amp integrator places a resistor in parallel with its feedback capacitor. What is the main purpose of this resistor?$

Op-amp RC circuits Medium

A.

To increase high-frequency differentiation

B.

To eliminate the input resistance

C.

To limit low-frequency and DC gain

D.

To increase the output offset voltage

39 $A passive RC low-pass stage attenuates the signal and is affected by the connected load. Which advantage does an op-amp active filter provide in this situation?$

Active filter Medium

A.

Voltage gain and impedance isolation

B.

Filtering without resistors or capacitors

C.

Operation without any power supply

D.

Unlimited bandwidth and zero noise

40 $In a simplified anti-lock braking system, an op-amp comparator receives a wheel-speed sensor voltage at its non-inverting input and a reference voltage at its inverting input. What happens when the sensor voltage falls below the reference?$

Application of op-amp comparator in anti-lock braking systems Medium

A.

The comparator output remains linear and amplifies the voltage difference

B.

The comparator output oscillates continuously at the wheel frequency

C.

The comparator output switches high to indicate increasing wheel speed

D.

The comparator output switches low to indicate possible wheel lock

41 $A band-pass filter is formed by cascading unloaded first-order high-pass and low-pass sections having cutoff frequencies and . What are the approximate magnitude and phase of the overall transfer function at ?$

Band-pass filter Hard

A.

with phase

B.

with phase

C.

with phase

D.

with phase

42 $A source with resistance drives an RC low-pass filter consisting of in series and to ground. The output is unloaded. What are the DC gain and the cutoff frequency measured from the ideal source voltage?$

Low-pass filter Hard

A.

and

B.

and

C.

and

D.

and

43 $For a first-order passive high-pass filter with transfer function, determine its magnitude and phase at .$

High-pass filter Hard

A.

and

B.

and

C.

and

D.

and

44 $A non-inverting amplifier has and . If the op-amp has a constant finite open-loop gain but is otherwise ideal, what is the closed-loop voltage gain?$

Operational amplifier abstraction Hard

A.

B.

C.

D.

45 $An op-amp has differential gain and CMRR . Its inputs have and . Assuming the output remains within its linear range, what output voltage is predicted when common-mode gain is included?$

Device properties of the operational amplifier Hard

A.

B.

C.

D.

46 $A voltage follower uses an op-amp with output swing limits of and output-current limits of . It drives a load connected to ground. Ignoring frequency limitations, what is the largest sinusoidal input peak that can be reproduced without distortion?$

Simple op-amp circuits Hard

A.

B.

C.

D.

47 $An inverting amplifier has,, and zero signal input. Both op-amp input bias currents are and flow into the device. The non-inverting input is grounded directly. Neglecting offset voltage, what is the output offset magnitude?$

Virtual ground concept Hard

A.

B.

C.

D.

48 $An inverting amplifier has,, and an op-amp gain-bandwidth product of . Using a single-pole op-amp model, what is the approximate signal-gain magnitude at ?$

Inverting op-amp Hard

A.

B.

C.

D.

49 $A non-inverting amplifier has,, and a source resistance of at its non-inverting input. What additional series resistance should be inserted to minimize output offset caused by equal input bias currents?$

Non-inverting op-amp Hard

A.

B.

C.

D.

50 $An inverting active high-pass filter uses a series input capacitor, input resistor, and feedback resistor . What are the approximate gain magnitude and phase at its cutoff frequency?$

Active high-pass filter Hard

A.

and

B.

and

C.

and

D.

and

51 $An active band-pass filter cascades buffered first-order high-pass and low-pass sections with and . The remaining amplifier stages provide a frequency-independent gain of . What is the output peak amplitude for a peak input at ?$

Active band-pass filter Hard

A.

B.

C.

D.

52 $An ideal notch filter has with . Component tolerances shift the actual notch frequency to . What is at the original frequency ?$

Active band-stop filter Hard

A.

B.

C.

D.

53 $An inverting summing amplifier has . Inputs,, and are applied through,, and, respectively. What is the output voltage?$

Op-amp as an adder Hard

A.

B.

C.

D.

54 $A differential amplifier has from to the inverting input and in feedback. At the non-inverting input, connects to and connects to ground. For, what output results from the resistor-ratio mismatch?$

Op-amp as a subtractor Hard

A.

B.

C.

D.

55 $A practical inverting integrator has and a feedback network consisting of in parallel with . At, approximately ten times its feedback pole frequency, what are the transfer-function magnitude and principal phase?$

Op-amp RC circuits Hard

A.

and

B.

and

C.

and

D.

and

56 $An ideal inverting integrator has,, and initial output . The input is for and then for . What is the final output?$

Op-amp integrator Hard

A.

B.

C.

D.

57 $An ideal inverting differentiator has and . For, what output peak and minimum required slew rate are expected?$

Op-amp differentiator Hard

A.

and

B.

and

C.

and

D.

and

58 $A second-order Sallen-Key low-pass filter uses equal resistors and equal capacitors. For this topology,, where is the non-inverting passband gain. Which gain produces a Butterworth response?$

Active filter Hard

A.

B.

C.

D.

59 $An inverting Schmitt comparator applies the input to the inverting terminal. The non-inverting terminal receives, and the op-amp saturates at . Starting at positive saturation, which switching thresholds apply as the input first rises and then falls?$

Op-amp as a comparator Hard

A.

It switches low at and high at

B.

It switches low at and high at

C.

It switches low at and high at

D.

It switches low at and high at

60 $An ABS comparator monitors with . It commands pressure release when and does not reapply pressure until . Starting in the pressure-applied state, successively becomes,,, and . What is the state after each sample?$

Application of op-amp comparator in anti-lock braking systems Hard

A.

Applied, released, applied, applied

B.

Released, released, released, applied

C.

Applied, applied, released, released

D.

Applied, released, released, applied

Unit 5: Fundamentals of filters and operational amplifier - Practice Quiz

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