In a cylindrical vessel of diameter 24 cm filled up with sufficient quantity of water, a solid spherical ball of radius 6 cm is completely immersed. Then the increase in height of water level is :

If the height of increased water level be h cm,

then $pi r^{2} h=frac{4}{3} pi mathrm{R}^{3}$

$Rightarrow 12 imes 12 imes h=frac{4}{3} imes 6 imes 6 imes 6$

$Rightarrow h=frac{4 imes 2 imes 6 imes 6}{12 imes 12}=2 mathrm{~cm}$