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GATE 2014 EC (EC4) – Question 23

Analog Circuits · Op-amp Circuits · 1 mark · Multiple choice

What does the circuit shown represent?

Diagram for GATE 2014 EC (EC4) question 23
  1. A bandpass filter
  2. A voltage-controlled oscillator
  3. An amplitude modulator
  4. A monostable multivibrator

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Show answer and explanation

Correct answer: (D) A monostable multivibrator

Explanation

At DC the positive-input capacitor is open and its resistor holds that input at0V, while the negative input rests at−2V, giving a stable positive output. A trigger through C2can switch the output temporarily; capacitive positive feedback through C1then decays through R1and returns it to the stable state. Thus this is **a monostable multivibrator,D**.