Question

Calculate the electric field strength required to just support a water drop of mass ${10}^{-7}$ kg and having a charge $1.6\times {10}^{-19}C.$

Answer 1

Here, $m=10;q=1.6\times {10}^{-19}C$
Let E be the strength of the electric field required to just support the water drop. Then,
$Ee=mg$

or $E=\frac{mg}{e}=\frac{{10}^{-7}\times 9.8}{1.6\times {10}^{-19}}$

$=6.125\times {10}^{12}N{C}^{-1}$