Problem $2(10$ pts$.,5$ pts$.$ for each circuit$)$

For each of the following diode circuits:

a$)$ Plot the output voltage $v_0$ as a function of time. $(4$ pts$.)$

b$)$ State the function of the circuit $($rectifier$,$ regulator, clipper, clamper, etc$)(1$ pt$.)$

Assume that all diodes have a cut$-$in voltage of $V_y=0\mathrm{.}7V$