Question

a certain inverting amplifier has a closed - loop gain of 25. the op - amp has an open - loop gain of 100,000. if another op - amp with an open - substituted in the configuration, the closed - loop gain
select one:
○ a. increases very slightly
○ b. drops to 12.5
○ c. stays 25
○ d. doubles

Explanation:

For an inverting op-amp amplifier, the closed-loop gain is determined by the external resistor values, following the formula $A_{CL} = -\frac{R_f}{R_{in}}$. This gain is nearly independent of the op-amp's open-loop gain, as long as the open-loop gain is very large (which is true for typical op-amps). Substituting another op-amp with a large open-loop gain will not change the closed-loop gain set by the external components, so it remains 25.

Answer:

c. stays 25