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Unit 5: Fundamentals of Filters and Operational Amplifiers - Practice Quiz

ECE131 — Basic Electrical And Electronics Engineering 50 Questions
0 Correct 0 Wrong 50 Left
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1 Which component is primarily used to select or reject a specific range of frequencies in an electronic circuit?

A. Filter
B. Transformer
C. Rectifier
D. Oscillator

2 An ideal low-pass filter allows signals to pass through it if their frequency is:

A. Exactly equal to the resonance frequency
B. Lower than the cut-off frequency
C. Higher than the cut-off frequency
D. Within a specific high-frequency band

3 What is the formula for the cut-off frequency () of a simple RC filter?

A.
B.
C.
D.

4 A high-pass filter can be constructed by swapping the position of the resistor and capacitor in which circuit?

A. Bridge rectifier
B. Voltage follower
C. Band-pass filter
D. Low-pass filter

5 Which filter type passes frequencies within a certain range and rejects frequencies outside that range?

A. High-pass filter
B. All-pass filter
C. Low-pass filter
D. Band-pass filter

6 In the context of filters, what does the term 'Stopband' refer to?

A. The frequency where gain is 0 dB
B. The range of frequencies that are allowed to pass
C. The range of frequencies that are attenuated
D. The phase shift of the signal

7 What is the ideal input impedance of an operational amplifier?

A. Infinite ()
B. Zero ()
C.
D.

8 What is the ideal output impedance of an operational amplifier?

A. Infinite ()
B.
C. Zero ()
D.

9 The open-loop voltage gain () of an ideal op-amp is:

A. 1
B. Infinite ()
C. 100
D. 0

10 Common Mode Rejection Ratio (CMRR) is the ratio of:

A. Common mode gain to Differential gain
B. Differential gain to Common mode gain
C. Input impedance to Output impedance
D. Output voltage to Input voltage

11 Which parameter defines the maximum rate of change of the output voltage per unit of time?

A. Offset Voltage
B. Slew Rate
C. Bandwidth
D. CMRR

12 The concept of 'Virtual Ground' is primarily applicable to which op-amp configuration?

A. Inverting amplifier with negative feedback
B. Open-loop comparator
C. Positive feedback oscillator
D. Voltage follower without feedback

13 Why does the concept of virtual ground exist in an ideal op-amp?

A. Because the slew rate is zero
B. Because the input impedance is zero
C. Because the output impedance is infinite
D. Because the open-loop gain is infinite

14 In an ideal op-amp circuit, the current entering the input terminals ( and ) is considered to be:

A. Zero
B. Infinite
C. Depends on the input voltage
D. 1 Ampere

15 What is the voltage gain () of an inverting amplifier with feedback resistor and input resistor ?

A.
B.
C.
D.

16 The phase shift introduced by an inverting op-amp configuration is:

A.
B.
C.
D.

17 What is the voltage gain () of a non-inverting amplifier?

A.
B.
C.
D.

18 If and in an inverting amplifier, what is the gain?

A. 5
B. -5
C. -0.2
D. 6

19 If and in a non-inverting amplifier, what is the gain?

A. 1
B. 0
C. -1
D. 2

20 Which op-amp configuration acts as a 'Voltage Follower' or 'Unity Gain Buffer'?

A. Summing amplifier
B. Non-inverting amplifier with and
C. Differentiator
D. Inverting amplifier with

21 What is the primary advantage of a Voltage Follower circuit?

A. It inverts the signal phase
B. It acts as an impedance matching buffer (high , low )
C. It amplifies voltage significantly
D. It filters out low frequencies

22 An op-amp summing amplifier (adder) is typically based on which configuration?

A. Comparator
B. Open-loop configuration
C. Inverting configuration
D. Voltage follower

23 In an inverting summing amplifier with three inputs and all resistors equal (), the output voltage is:

A.
B.
C.
D.

24 To convert a summing amplifier into an averaging amplifier for 3 inputs, the ratio should be:

A. Infinite
B. 1
C.
D. 3

25 An op-amp subtractor (difference amplifier) produces an output proportional to:

A. The product of the two input voltages
B. The integral of the input voltage
C. The sum of the two input voltages
D. The difference between the two input voltages

26 In a basic differential amplifier (subtractor) circuit, if all external resistors are equal, the output voltage is:

A.
B.
C.
D.

27 Which op-amp circuit performs the mathematical operation of integration?

A. Differentiator
B. Adder
C. Integrator
D. Comparator

28 In an ideal op-amp integrator circuit, the feedback element is a:

A. Diode
B. Resistor
C. Inductor
D. Capacitor

29 If a constant DC voltage is applied to the input of an ideal op-amp integrator, the output will be:

A. A sine wave
B. A ramp voltage (linear increase/decrease)
C. A constant DC voltage
D. Zero

30 The output voltage of an ideal integrator is given by:

A.
B.
C.
D.

31 In an op-amp differentiator circuit, the input element is a __ and the feedback element is a __.

A. Resistor, Resistor
B. Capacitor, Resistor
C. Resistor, Capacitor
D. Capacitor, Capacitor

32 If the input to an ideal differentiator is a triangular wave, the output will be:

A. A cosine wave
B. A triangular wave
C. A square wave
D. A sine wave

33 A major practical disadvantage of the ideal differentiator circuit is:

A. It amplifies high-frequency noise
B. It cannot be built with standard components
C. It has very low input impedance
D. It blocks DC signals

34 When an op-amp is used as a comparator, it typically operates in which mode?

A. Closed-loop with negative feedback
B. Active region
C. Unity gain mode
D. Open-loop (no feedback)

35 In a comparator circuit, if the voltage at the non-inverting input () is greater than the voltage at the inverting input (), the output goes to:

A. Negative Saturation ()
B.
C.
D. Positive Saturation ()

36 Which application is a primary use of an op-amp comparator in Anti-lock Braking Systems (ABS)?

A. Differentiation of the steering angle
B. Integrating the brake pressure
C. Converting wheel speed sensor signals to digital pulses
D. Amplifying the audio signal for the driver

37 In an ABS system, the comparator typically compares the wheel speed sensor signal against:

A. The battery voltage
B. A fixed reference voltage (e.g., Ground)
C. The engine temperature
D. The output of the alternator

38 Why is negative feedback generally NOT used in a simple comparator circuit?

A. It creates instability
B. It slows down the switching speed
C. It reduces the gain too much
D. It is used; this statement is false

39 What happens if a differentiator input is a sine wave: ?

A.
B. is zero
C.
D.

40 In a practical integrator, a resistor is often placed in parallel with the feedback capacitor to:

A. Increase the slew rate
B. Reduce the gain at low frequencies (prevent saturation due to offsets)
C. Convert it to a differentiator
D. Increase the bandwidth

41 Bandwidth of an ideal op-amp is:

A. Finite
B.
C. Infinite
D.

42 What is the slope of the frequency response roll-off for a first-order Low-pass RC filter?

A.
B.
C.
D.

43 Which component determines the 'order' of a passive filter?

A. The number of reactive components (Capacitors/Inductors)
B. The resistor value
C. The voltage source
D. The load resistance

44 An op-amp usually requires which type of power supply?

A. Single AC source
B. High voltage AC
C. Current source only
D. Dual polarity DC supply ( and )

45 In an inverting amplifier, if the input signal is peak-to-peak sine wave and gain is -2, the output is:

A. peak-to-peak sine wave
B. peak-to-peak sine wave, in phase
C. peak-to-peak sine wave
D. peak-to-peak sine wave, phase shifted

46 Which of the following is NOT a property of an ideal Op-Amp?

A. Infinite Input Impedance
B. Infinite Open Loop Gain
C. Infinite Output Impedance
D. Infinite Bandwidth

47 In an ABS system, if a wheel locks up (stops rotating), the frequency of the pulses from the wheel speed sensor (processed by the comparator) will:

A. Drop to zero
B. Remain constant
C. Invert polarity
D. Increase to infinity

48 A Band-pass filter is effectively a cascade combination of:

A. Two High-pass filters
B. Two Low-pass filters
C. An integrator and a differentiator
D. A High-pass filter and a Low-pass filter (with overlapping passbands)

49 In a non-inverting amplifier, the input signal is applied to:

A. The inverting terminal (-)
B. The non-inverting terminal (-)
C. The output terminal
D. The feedback resistor

50 The voltage at the non-inverting input of an inverting amplifier (connected to ground) is:

A.
B.
C.
D.
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