$\Rightarrow \quad 20=\omega^{2}(5) \Rightarrow \omega=2 \mathrm{rad} \mathrm{s}^{-1}$
$\therefore \quad$ Time period of oscillation, $T=\frac{2 \pi}{\omega}=\frac{2 \pi}{2}=\pi \mathrm{s}$





Statement $I :$ A second's pendulum has a time period of $1$ second.
Statement $II :$ It takes precisely one second to move between the two extreme positions.
In the light of the above statements, choose the correct answer from the options given below: