Redraw the circuit of, but with an additional 20-kV resistance between the node labeled vO and ground. (a) Specify suitable values for VS and R1 through R4 to implement a symmetric VTC that goes...

Redraw the circuit of, but with an additional 20-kV resistance between the node labeled vO and ground. (a) Specify suitable values for VS and R1 through R4 to implement a symmetric VTC that goes through the origin and has a slope of 1y2 V/V for uvI u # 6 V, a slope of 1y3 V/V for 6 V # uvI u # 12 V, and a slope of 0 V/V for uvI u $ 12 V. Hint: exploit the symmetry of the VTC, draw it for the case for vI $ 0, and show the subcircuit corresponding to each of its three segments. (b) What happens to the VTC if D2 and D4 are removed? (c) What happens to the VTC if the value of VS is doubled?