$$R-L-C$$ circuit shown in figure

For a step input $${e_{i,}}$$ the overshoot in the output $${e_{0,}}$$ will be

$$R-L-C$$ circuit shown in figure

If the above step response is to be observed on a non - storage $$CRO,$$ then it would be best have the $${e_i}$$ as a

The system shown in the figure is

If the loop gain $$K$$ of a negative feedback system having a loop transfer function $$K\left( {s + 3} \right)/{\left( {s + 8} \right)^2}$$ is to be adjusted to induce a sustained oscillation then