In closed-loop analog design, a noninverting operational amplifier (op-amp) connects the input signal to the op-amp's noninverting (+) terminal and uses a feedback divider from the output to the inverting (−) terminal. In typical textbook implementations where the feedback network is resistive, what is the usual range of the closed-loop gain for a noninverting configuration?

Introduction:
A noninverting closed-loop op-amp is foundational in analog electronics. This question tests whether you know the characteristic gain behavior of the noninverting topology, which is widely used for signal buffering and amplification with high input impedance and predictable closed-loop gain.

Given Data / Assumptions:

• Standard noninverting op-amp configuration using a resistive feedback divider.
• Ideal op-amp assumptions for clarity: infinite open-loop gain, infinite input impedance, zero output impedance.
• No special gain-reducing elements like attenuators at the input.

Concept / Approach:
The closed-loop gain of the canonical noninverting amplifier is Av = 1 + (Rf / Rin), where Rf is the feedback resistor (output to − input) and Rin is the resistor from the − input to ground (or reference). Because Rf / Rin ≥ 0 for passive resistors, Av is always ≥ 1, equaling 1 only when Rf = 0 (voltage follower) and strictly greater than 1 when Rf > 0.

Step-by-Step Solution:
1) Write the noninverting gain: Av = 1 + (Rf / Rin).2) Note that passive resistors imply Rf ≥ 0 and Rin > 0 in typical designs.3) Therefore, Rf / Rin ≥ 0, so Av ≥ 1.4) For amplification (not just buffering), choose Rf > 0 to obtain Av > 1.

Verification / Alternative check:
Consider the limiting case Rf = 0. Then Av = 1 (a unity-gain buffer). Any positive Rf raises gain above 1, confirming the general rule that noninverting closed-loop gain is typically greater than one.

Why Other Options Are Wrong:
Less than one: contradicts Av = 1 + (Rf / Rin) for passive components.Of zero: physically meaningless for closed-loop voltage gain.Equal to one: only for the buffer case; generally the configuration is designed for > 1.

Common Pitfalls:
Confusing noninverting with inverting gain formula or forgetting the added +1 term specific to the noninverting topology.

Final Answer:
greater than one