Question

The input impedance of an ideal op-amp is

• A. Zero
• B. Finite
• C. Very low
• D. Infinite

Hint:

Ideal op-amp characteristics: \[ \boxed{ \begin{aligned} A_{OL}&=\infty, R_{in}&=\infty, R_{out}&=0. \end{aligned} } \]

Answer 1

The Correct Option is D

Step 1: Recall the characteristics of an ideal operational amplifier. An ideal op-amp has \[ \begin{aligned} &\text{Infinite input impedance}, &\text{Zero output impedance}, &\text{Infinite open-loop gain}. \end{aligned} \]

Step 2: Choose the correct option. Since the input impedance is infinite, the op-amp draws no input current. Hence, \[ \boxed{\text{Infinite}} \] Therefore, \[ \boxed{(D)} \] is the correct answer.