A vertical electric field of magnitude $4.9 × 105 NC^{-1}$ just prevents a water droplet of mass 0.1 g from falling. What is the charge on the droplet ? Take acceleration due to gravity $9.8 ms^{-2}$.

$2.0 × 10^{-9} C$ $2.0 × 10^{-6} C$ $5.0 × 10^{5} C$ $5.0 × 10^{6} C$

$2.0 × 10^{-9} C$

The correct answer is Option (1) → $2.0 × 10^{-9} C$