Answer
$q=56pC$
Work Step by Step
As we know that
$E=\frac{q}{4\pi{\epsilon_{\circ}}r^2}$
or
$q=4\pi{\epsilon_{\circ}}r^2E$
Putting the values
$q=4(3.14)(8.854\times10^{-12})(50\times10^{-2})^2(2.00)$
$q=5.56\times10^{-11}C$
$q=55.6\times10^{-1}\times10^{-11}C$
$q=55.6\times10^{-12}C$
or
$q=56pC$
