Statement I : Orbital angular momentum of 4s orbital is zero.
Statement II : Angular momentum of electron in 4th orbit of H atom is  $\frac{\mathrm{h}}{2\mathrm{\pi }}$

Orbital Angular momentum = $\sqrt{\mathrm{l}\left(\mathrm{l}+1\right)}\frac{\mathrm{h}}{2\mathrm{\pi }}\left(\mathrm{l}=0\mathrm{for}\mathrm{s}-\mathrm{orbital}\right)$

                                                    $\begin{array}{l}=\sqrt{0\left(0+1\right)}\frac{\mathrm{h}}{2\mathrm{\pi }}\\ =0\end{array}$

II) Angular momentum of electron in 4th orbit, $\mathrm{mvr}=\frac{\mathrm{nh}}{2\mathrm{\pi }}=\frac{4\mathrm{h}}{2\mathrm{\pi }}=\frac{2\mathrm{h}}{\mathrm{\pi }}$