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GATE 2014 EC (EC1) – Question 21

Analog Circuits · BJT and MOSFET Amplifiers · 1 mark · Multiple choice

A good current buffer has ______.

  1. low input and low output impedance
  2. low input and high output impedance
  3. high input and low output impedance
  4. high input and high output impedance

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Correct answer: (B) low input and high output impedance

Explanation

A current buffer should accept the source current without diverting it through an input voltage drop, so its input impedance should be low. It should deliver that current nearly independently of the load voltage, requiring high output impedance. Hence **low input,high output,B**.