\begin{tabular}{|l|l|}
\hline Q.38 & $\begin{array}{l}\text { Consider a lead compensator of the form } \\
\qquad K(s)=\frac{1+\frac{s}{a}}{1+\frac{s}{\beta a}}, \beta>1, a>0 \\
\text { The frequency at which this compensator produces maximum phase lead is } 4 \mathrm{rad} / \mathrm{s} . \\
\text { At this frequency, the gain amplification provided by the controller, assuming } \\
\text { asymptotic Bode-magnitude plot of } K(s), \text { is } 6 \mathrm{~dB} \text {. The values of } a, \beta, \text { respectively, } \\
\text { are }\end{array}$ \\
\hline
- & 1,16 \\
\hline - & 2,4 \\
\hline - & 3,5 \\
\hline - & $2.66,2.25$ \\
\hline & \\
\hline
\end{tabular}