Solid sphere A is rotating about an axis P Q . If the radius of the sphere is 5   cm , then its radius…

Solid sphere $A$ is rotating about an axis $PQ$. If the radius of the sphere is $5 \mathrm{cm}$, then its radius of gyration about $PQ$ will be $\sqrt{x} \mathrm{cm}$. The value of $x$ is _____.