An oil droplet of very small mass $m$ has a charge of $+q$. The p.d. between the plates is $V$ and their spacing is $d$. The droplet’s weight is equal to the electric force. (The buoyancy forces can be taken as negligible.) Which formula gives the charge on the drop?
- A$q=\frac{mgd}{V}$
- B$q=\frac{mgV}{d}$
- C$q=\frac{Vd}{mg}$
- D$q=\frac{V}{mgd}$