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GATE 2014 EC (EC4) – Question 22

Analog Circuits · Diode Circuits · 1 mark · Multiple choice

Two silicon diodes with forward drop 0.7 V form the circuit shown. Find the input-voltage range for which V₀ = V_i.

Diagram for GATE 2014 EC (EC4) question 22
  1. $-0.3<V_i<1.3$ V
  2. $-0.3<V_i<2.0$ V
  3. $-1.0<V_i<2.0$ V
  4. $-1.7<V_i<2.7$ V

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Show answer and explanation

Correct answer: (D) $-1.7<V_i<2.7$ V

Explanation

The lower limiter begins conducting when the output drops below−1−0.7=−1.7V. The upper limiter conducts when output rises above2+0.7=2.7V. Between these thresholds both branches are open and there is no resistor voltage drop, so **Vo=Vi for−1.7<Vi<2.7V,D**.