Answer
$E=7.0\times 10^5\frac{V}{m}$
Work Step by Step
We know that
$E=\frac{\Delta V}{\Delta d}$
We plug in the known values to obtain:
$E=\frac{0.070}{0.10\times 10^{-6}}$
$E=7.0\times 10^5\frac{V}{m}$
As we know that the electric field is directed from higher to lower potential, thus the electric field is directed inward across the cell membrane.