Voltage follower property — a unity-gain buffer (voltage follower) has a fixed closed-loop voltage gain approximately equal to 1, not 10. Is the statement “gain ≈ 10” appropriate for a voltage follower?

Introduction / Context:
A voltage follower (also called a unity-gain buffer) connects the op-amp output directly to the inverting input and applies the signal to the non-inverting input. The closed-loop gain is approximately +1, providing high input impedance, low output impedance, and isolation without amplifying the voltage magnitude. The prompt claims a fixed gain near 10, which describes a different non-inverting amplifier configuration with an external resistor divider, not a follower.

Given Data / Assumptions:

• Standard op-amp operated within linear region and bandwidth limits.
• Unity-feedback topology for a voltage follower.
• Neglect small gain error due to finite open-loop gain and frequency response.

Concept / Approach:
For a non-inverting amplifier with feedback network, the closed-loop gain is Av = 1 + (Rf/Rg). A follower is the special case Rf → ∞ and Rg → ∞ replaced by a direct short from output to inverting input, yielding Av ≈ 1. Any gain near 10 would require explicit resistor values (e.g., Rf/Rg ≈ 9), which is not a unity follower.

Step-by-Step Solution:

Verification / Alternative check:
Measure Vout/Vin of an actual follower over frequency within the device’s bandwidth; it will track ~1 with minimal phase/amp error until roll-off.

Why Other Options Are Wrong:

Common Pitfalls:
Using the term “buffer” for any non-inverting stage regardless of gain; ignoring finite bandwidth and stability considerations which slightly alter unity gain at extremes.

Final Answer:
Incorrect — a voltage follower has gain ≈ 1