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GATE 2014 EC (EC3) – Question 48

Analog Circuits · Op-amp Circuits · 2 marks · Multiple choice

For the ideal op-amp circuit shown, find V₀.

Diagram for GATE 2014 EC (EC3) question 48
  1. $\frac52V_1-3V_2$
  2. $2V_1-\frac52V_2$
  3. $-\frac32V_1+\frac72V_2$
  4. $-3V_1+\frac{11}2V_2$

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Show answer and explanation

Correct answer: (D) $-3V_1+\frac{11}2V_2$

Explanation

Negative feedback sets the inverting node equal to V2. KCL there gives(V2−V1)/R+V2/(2R)+(V2−Vo)/(3R)=0. Multiply by3R and solve:Vo=−3V1+(3+1.5+1)V2=**−3V1+(11/2)V2,D**. The output load does not affect an ideal op-amp’s voltage.