Answer
The magnitude of the charge on each electrode is $14~nC$
Work Step by Step
We can use the expression for the electric field strength in a plate capacitor to find the charge on each electrode.
$E = \frac{\sigma}{\epsilon_0}$
$E = \frac{Q}{A~\epsilon_0}$
$Q = E~A~\epsilon_0$
$Q = (1.0\times 10^6~N/C)(0.040~m)(0.040~m)(8.85\times 10^{-12}~C^2/N~m^2)$
$Q = 1.4\times 10^{-8}~C$
$Q = 14~nC$
The magnitude of the charge on each electrode is $14~nC$.
