Answer
$C=4.20\times 10^{-9}F$
$A=0.247m^2$
Work Step by Step
We know that:
$Q=CV$
But;
$V=Ed$
$\implies Q=C(Ed)$
This can be rearranged as
$C=\frac{Q}{Ed}$
We plug in the known values to obtain:
$C=\frac{0.675\times 10^{-6}}{8.24\times 10^4\times 1.95\times 10^{-3}}=4.20\times 10^{-9}F$
We also know that:
$C=K\epsilon_{\circ}\frac{A}{d}$
This can be rearranged as
$A=\frac{Cd}{K\epsilon_{\circ}}$
We plug in the known values to obtain:
$A=\frac{4.20\times 10^{-9}(1.95\times 10^{-3})}{3.75(8.85\times 10^{-12})}=0.247m^2$
