The volume charge density of a sphere of radius \( 6 \, \text{m} \) is \( 2 \, \mu\text{C cm}^{-3} \). The number of lines of force per unit surface area coming out from the surface of the sphere is ________ \( \times 10^{10} \, \text{N C}^{-1} \).
(Given : Permittivity of vacuum \( \in_{0} = 8.85 \times 10^{-12} \, \text{C}^{2} \text{N}^{-1} \text{m}^{-2} \))
