The diagram depicts two horizontal metal plates arranged in parallel. The upper plate carries positive charge, while the lower plate is earthed. A tiny charged liquid drop, positioned halfway between the plates, remains in equilibrium because its weight is balanced by the electric force acting on it. The acceleration of free fall is $g$ and the electric field strength is $E$. What polarity does the charge on the drop have, and what is the ratio of charge to mass of the drop?
- Anegative, $\frac{E}{g}$
- Bnegative, $\frac{g}{E}$
- Cpositive, $\frac{E}{g}$
- Dpositive, $\frac{g}{E}$