. Consider IREF = 0.25 mA. What is the range of output voltage for which the circuit operates as a small-signal amplifier? (Hint: What should be the region of operation for both devices?)B. If we wish to increase the value of IREF, this can be done by RREF and by R2. C. If IREF is made a factor of 4 greater, by what factor will gm1 change? Justify your answer with a supporting equation. D. If IREF is made a factor of 4 greater, by what factor will the amplifier circuit’s output resistance, Routchange? Justify your answer with a supporting equation. E. If IREF is made a factor of 4 greater, by what factor will the amplifier circuit’s voltage gain, vo/vichange? Justify your answer with a supporting equat