Hi. In Roberge's Op Amp book (2007 2nd ed) there is this practice problem:
Assume that the operational-amplifier connection shown in Fig. 1.10
> satisfies the two conditions stated in Section 1.2.2. Use these
> conditions to determine the output resistance of the connection (i.e.,
> the resistance seen by the load).
With the indicated conditions being:
1. A negligibly small differential voltage applied between the two input
> terminals of the amplifier is sufficient to produce any desired output > voltage.
> 2. The current required at either amplifier terminal is negligibly > small.
Here is a reproduction of the diagram, basically just a non-inverting amplifier:
``` ╷\ ╭─────┤+\ ╵ │ \ Vi │ /╶──╮ ╷ ╭─┤-/ ╭─┴──╮ ╵ │ ╵/ │LOAD│ GND │ ╰─┬──╯ ╰────────┤ ╵ R ╷ ╵ GND ```
Is this a more complicated problem than it appears to be on the surface? The output resistance is just the resistor R, right? Or do I have to prove that?