The GATE Grind

GATE 2025 IN – Question 31

Analog Electronics · Operational amplifiers and applications · 1 mark · Multiple select

The circuits mentioned in the following options are realized using ideal opamp. Among these, the circuit(s) performing non-linear operation on the input signal is/are

  1. Instrumentation amplifier
  2. Schmitt trigger
  3. Logarithmic amplifier
  4. Precision rectifier

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Show answer and explanation

Correct answer: (B) Schmitt trigger; (C) Logarithmic amplifier; (D) Precision rectifier

Explanation

A Schmitt trigger has hysteretic threshold switching, a logarithmic amplifier has a logarithmic input–output law, and a precision rectifier changes behaviour with input polarity.

All violate superposition.

An instrumentation amplifier has a linear gain relation in its operating range.

Thus **B,C,D**.