Getting confused on understanding how opamp works with zener in Feedback loop. Referring to the ckt here (attached.) (replace diode with 5V zener) Using virtual short, when the input voltage is zero, opamp output is 5V? Basically the opamp sources current into the zener. When the input is -1V, the opamp output is still 5v? Opamp has to pump 5V to keep the zener conducting. The current flows from output of opamp thru the zener into the input resistor and to the -1v souce? The current flowing in the resistor will be (-1/R)?