What will the input resistance and output resistance be if R1 = 800 kΩ, R2 = 4R4 = 2 MΩ, and R3 = 80kΩ? Assume an ideal operational amplifier.
4. The op-amp in the circuit has an input resistance of 400kΩ, an output resistance of 4kΩ, and an open-loop gain, A, of 200,000. Assume the opamp is operating in its linear region. a. Calculate the voltage gain (vO/vS) of the amplifier. b. Calculate the value of vl in µV when vS = 1 V. c. Calculate the resistance seen by the signal source vS (we usually call this the input impedance of the amplifier circuit). d. Repeat (a), (b), and (c) using the ideal model for the op-amp.