The linear charge density of an infinite line charge producing a uniform electric field of $9 \times 10^6 ~N / C$ at a distance of 2 cm is :

(Take permittivity of vacuum $\epsilon_0=8.85 \times 10^{-12} C^2 ~N^{-1} ~m^{-2}$)

$10 \mu C / m$

$ E = \frac{\lambda}{2\pi \epsilon_0 r} = \frac{2\times 9\times 10^9\times \lambda}{2\times 10^{-2}} = 9\times 10^6$

$ \lambda = \frac{9\times 10^6 \times 2\times 10^{-2}}{18\times 10^9}= 10^{-5}=10\mu C/m$