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Ideal OPAMP Problem Solution Consider the circuit with an ideal OPAMP shown in the figure. Assuming |V IN | << |V CC | and |V REF | << |V CC |, determine the condition at which V OUT = 0 . Options: V IN = V REF V IN = 0.5 V REF V IN = 2 V REF V IN = 2 + V REF Solution Step 1: Identify the Op-Amp Configuration The non-inverting terminal (+) is connected to ground. Therefore, V + = 0 V Since the op-amp is ideal and operates with negative feedback, the inverting terminal is also at virtual ground. V - = V + = 0 V Step 2: Apply KCL at the Inverting Node Three currents meet at the inverting input: Current from V IN Current from V REF Feedback current through R F Current due to V IN I 1 = (V IN - 0)/R = V IN /R Current due to V REF Observe the polarity of the V REF source. Its positive terminal is connected to ground. Hence the resistor is connected to a voltage of -V REF . I 2 = (-V REF - 0)/R ...