Problem 1 (30 points). Difference Amplifier
Consider the circuit of Figure 1a:
1a) 10 points: The Op Amp is ideal and is biased by $+V = 10$ V and 0 V. Sketch the transfer characteristics (TC) $v_o = f(v_i)$ for the range $-2$ V $\leq v_i \leq 12$ V. Indicate the critical values of $v_i$ and $v_o$ in your sketch.
1b) 10 points: An input voltage $v_i(t) = 10 \sin(\omega t)$ V is applied to the difference amplifier, resulting in the output voltage shown in Figure 1b. Explain using numbers why these waveforms are consistent with the TC that you obtained in part a).
1c) 10 points: Calculate current $i_1$. Calculate the value of current $i_1$ when the input voltage has the value $v_i = 7$ V. Assuming the Op Amp is operating in the linear region, what is the equation for $i_1 = f(v_i)$?
