A charged particle lies in the electric field between two horizontal metal plates that are connected to a source of constant potential difference, as shown in the diagram. The electric field exerts a force $F$ on the particle. If the distance between the plates is doubled, what force will now act on the particle?
- A$\frac{F}{4}$
- B$\frac{F}{2}$
- C$F$
- D$2F$