Assume that the conduction angle of the silicon diodes shown in the circuit of Figure P11.13 is:
$$
\begin{aligned}
& \phi=23^{\circ} \\
& v_{\text {s1 }}(t)=v_{s 2}(t)=8 \cos (\omega t) \mathrm{V} \\
& \omega=377 \mathrm{rad} / \mathrm{s} \quad R_{\sharp}=20 \mathrm{k} \Omega \\
& C=0.5 \mu \mathrm{~F}
\end{aligned}
$$
Determine the rms value of the ripple voltage.