In the infinite plance, $y=6 \mathrm{~m}$, there exists a uniform surface charge density of $(1600 \; \pi)$ $\mu \mathrm{C} / \mathrm{m}^{2}$. The associated electric field strength is
- $30 \; \mathrm{iV} / \mathrm{m}$
- $30 \; \mathrm{jV} / \mathrm{m}$
- $30 \; \mathrm{kV} / \mathrm{m}$
- $60 \; \mathrm{iV} / \mathrm{m}$