Chapter 14, Problem 14.13EP

For the op−amp circuit shown in Figure 14.28, the parameters are $R_1=20\text{k}\Omega$ and $R_2=120\text{k}\Omega$ . (a) Let $I_{B1}=I_{B2}=0.8\mu \text{A}$ . (i) Can $R_3$ be adjusted such that ${\upsilon }_O=0$ ? (ii) if so, what is the value of $R_3$ ? (b) Repeat part (a) if $I_{B1}=0.75\mu \text{A}$ and $I_{B2}=0.85\mu \text{A}$ . (Ans. (a) $R_3=17.14\text{k}\Omega$ ,(b) $R_3=15.13\text{k}\Omega$ )