Match List I with List II Choose the correct answer from the options given below:LIST I LIST II A. Butterworth filter of order '2' I. Impedance matching B. Buffer II. CMRR = ∞ (infinity) C. Schmitt Trigger III. Positive feedback D. Ideal OPAMP IV. 40 dB/decade roll off
A-IV, B-I, C-III, D-II
Match each block to its defining property.
A → IV, second-order Butterworth: 40 dB/decade roll-off. Every pole adds 20 dB/decade of stopband attenuation, so an order-n filter falls at
\(20n\ \text{dB/decade} \Rightarrow 2\times 20 = 40\ \text{dB/decade}\)
(equivalently 12 dB/octave). The Butterworth response is maximally flat in the passband, \(|H(j\omega)|=1/\sqrt{1+(\omega/\omega_c)^{2n}}\), and is −3 dB at cut-off for every order.
B → I, buffer: impedance matching. A voltage follower has unity gain but an extremely high input impedance and a very low output impedance. It therefore takes almost no current from the source and can drive a heavy load — isolating a high-impedance sensor from a low-impedance stage so that no signal is lost in loading. (In the op-amp world "impedance matching" here means impedance isolation/buffering, not the conjugate matching of RF work.)
C → III, Schmitt trigger: positive feedback. A fraction of the output is fed back to the non-inverting input, so the switching threshold moves with the output state. That gives two distinct trip points — hysteresis:
\(V_{UT}=\dfrac{R_1}{R_1+R_2}V_{sat}, \qquad V_{LT}=-\dfrac{R_1}{R_1+R_2}V_{sat}\)
The gap between them makes the output immune to noise on a slowly changing input, and squares up ragged waveforms.
D → II, ideal op-amp: CMRR = ∞. The common-mode rejection ratio \(CMRR = A_d/A_{cm}\) is infinite for an ideal op-amp because its common-mode gain is zero — it responds solely to the difference between its inputs and completely ignores any signal common to both. This is what lets a difference amplifier extract a small differential signal riding on a large common-mode voltage or noise pickup.
Hence, the correct matching is A-IV, B-I, C-III, D-II.
Similar Questions
Assertion (A) : An Op-Amp is a direct coupled high gain amplifier.
Reason (R) : It consists of one or more differential amplifiers and usually followed by a level translator and push pull stage.
The input to a differentiator is –5 V. Its output will be
Match the following :
List – I List – II a. h-parameters i. O/P voltage varies as the slope of i/p voltage b. differentiator ii. Noise division c. half-wave rectifier iii. Function of a Q point d. integrator iv. series diode clipper Codes :
Assertion (A) : Op-Amp is used for sensor circuit.
Reason (R) : A small signal amplifier amplify weak measured signals.
Consider the following circuit, the switch S1 allows the output to switch between two ranges of amplitudes from 0-0.1 V and 0-1 V. Arrange these values of R1, R2 and R3 in increasing order.
(A) Value of R1
(B) Value of R2
(C) Value of R3Choose the most appropriate answer from the options given below :
The given operational amplifier circuit corresponds to which electronic circuit application ?
Statements in connection to Op-Amp applications are :
A. If we use a square wave generator followed by integrator circuit we get a triangular wave at the output
B. The logarithmic amplifier called a log-amplifier or a logger, is basically a current to voltage converter.
C.
is a first order high pass filter with voltage followerD. If we use a square wave generator followed by a clipping circuit then we get a saw-tooth wave generator.
Choose the correct answer from the options given below:
Match List I with List II
LIST I LIST II A. Single polarity positive voltage clipper circuit I. 
B. Negative clamping circuit II. 
C. Differentiator circuit III. 
D. Logarithmic Amplifier IV. 
Choose the correct answer from the options given below:
The correct flow in the basic block diagram of op-Amp is
A. Complementary symmetry push pull amplifier block.
B. Dual input unbalanced output differential amplifier block
C. Emitter follower with constant current source block
D. Dual-Input balanced output differential amplifier block
Choose the correct answer from the options given below :
Match the following :
List - I List - II a) 
i) 
b) 
ii) 
c) 
iii) 
d) 
iv) 
Codes :
Important Questions from Op-Amp and Its Applications
In the circuit shown below, $R$ is $1\text{ k}\Omega$ and $R_f$ is $10\text{ k}\Omega$. If $V_{\text{in}}$ is $100\text{ mV}$ and the op-amps have supply voltages of $\pm 15\text{ V}$, then $V_{\text{out}}$ is _______ V.
For IC 741 circuit shown below, the maximum input frequency above which the output will be distorted is ____________.
Assume that an op-amp 741 connected as a unit gain inverting amplifier is applied with an input change of 10 V. Determine the time taken for the output to change by 10 V. [Slew rate for op-amp 741 = 0.5 V/µs]
What is the value of output voltage $V_o$ in the given circuit? Assume op-amp to be ideal and MOSFET operating in saturation region.
In an ideal op-amp, the common mode gain is _____________.
