The GATE Grind

GATE 2025 PH – Question 65

Electronics · oscillators, operational amplifiers and their applications, active filters · 2 marks · Numerical answer

The figure shows an opamp circuit with a 5.1 V Zener diode in the feedback loop. The opamp runs from ±15 V supplies. If a +1V signal is applied at the input, the output voltage (rounded off to one decimal place) is ____

Non-inverting op-amp with a 5.1 V Zener in series with the 1 kΩ feedback resistor.

Practise this question in The GATE Grind →

Show answer and explanation

Correct answer: 7.06 to 7.14

Explanation

Negative feedback sets the inverting input at 1 V. The grounded 1 kΩ resistor draws 1 mA, requiring a 1 V drop across the series feedback resistor. The Zener adds 5.1 V, so output is $1+1+5.1=7.1$ V.