Ideal op-amp traits — choosing the third property Three traits make op-amps nearly ideal for many designs: very high input impedance, very low output impedance, and which third characteristic?

Introduction / Context:Idealized operational amplifiers are defined by extreme parameters that, with feedback, yield precise, predictable closed-loop behavior. Knowing these traits helps explain why feedback linearizes and stabilizes amplifier circuits.

Given Data / Assumptions:

• Ideal op-amp: infinite open-loop voltage gain, infinite input impedance, zero output impedance.
• Real op-amps approximate these properties to varying degrees.

Concept / Approach:A very high open-loop voltage gain ensures that even tiny input differences drive the output such that the feedback forces the inputs to be nearly equal (virtual short). This is the cornerstone of linear closed-loop gain set by passive components.

Step-by-Step Solution:Recall the three “ideals” commonly cited.High open-loop gain → accurate closed-loop gain via feedback.Therefore, select “Very high voltage gain”.

Verification / Alternative check:Datasheets list open-loop gains of 10^5 to 10^6; feedback reduces sensitivity to device variations, realizing accurate closed-loop gains.

Why Other Options Are Wrong:

• Unlimited bandwidth: No real device; gain-bandwidth product is finite.
• Low slew rate: Opposite of desirable; higher slew rate is preferred.
• Very high current gain: Not the primary idealized trait for op-amps.

Common Pitfalls:

• Confusing current gain with voltage gain in op-amp contexts.

Final Answer:Very high voltage gain