Consider the diff-amp with active load in Figure PI 1.66. The Early voltages are VAN = 120...

Consider the diff-amp with active load in Figure PI 1.66. The Early voltages are VAN = 120 V for Q1 and Q2 and VAP = 80 V for Q3 and Q4. (a) Determine the open-circuit differential-mode voltage gain, (b) Compare this value to the gain obtained when R = 0. (c) Determine the output resistance Ro for parts (a) and (b). Assume β = 100. [Hint: As a good approximation, use the output resistance results from a Widlar current source.]