The GATE Grind

GATE 2026 EE – Question 37

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

In the circuit shown, the open loop gain of the operational amplifier is $A_0=10^5$.

What is the voltage gain of the circuit?

(Round off to two decimal places)

Diagram for GATE 2026 EE question 37
  1. −16.67
  2. −20.00
  3. −21.00
  4. 12.67

Practise this question in The GATE Grind →

Show answer and explanation

Correct answer: (B) −20.00

Explanation

This is an inverting amplifier with $R_f=100$ kΩ and $R_{in}=5$ kΩ. With finite gain, $A_v=-\dfrac{R_f/R_{in}}{1+\frac{1+R_f/R_{in}}{A_0}}=-\dfrac{20}{1+21/10^5}=-19.996\approx-20.00$. The output is $-20\times0.1=-2$ V, well within the ±15 V supply.