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GATE 2014 EE (EE1) – Question 59

Analog and Digital Electronics · Operational amplifiers: characteristics and applications · 2 marks · Multiple choice

For ideal op-amps in the circuit shown, find V₀.

Diagram for GATE 2014 EE (EE1) question 59
  1. $V_1-V_2$
  2. $2(V_1-V_2)$
  3. $(V_1-V_2)/2$
  4. $V_1+V_2$

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Show answer and explanation

Correct answer: (B) $2(V_1-V_2)$

Explanation

At the two first-stage inverting nodes the ideal feedback voltages equal V2and V1. The2Rlink gives upper output U2=(3/2)V2−(1/2)V1and lower output U1=(3/2)V1−(1/2)V2. The final equal-resistor difference stage gives V0=U1−U2=**2(V1−V2),B**.