Two parallel plates have a potential difference between them. The distance between the plates is halved, but the electric field between them remains constant. How did the potential difference change?

A. Potential difference was halved.

B. Potential difference did not change.

C. Potential difference was doubled.

D. Potential difference was quadrupled.

For a set of very long (essentially infinitely long) charged parallel plates, the electric field between them is constant, and the electric field is given by

E = ΔV/d

ΔV is the potential difference between the plates and d is the distance of their separation.

If d is halved but E stays constant, then by the relationship above, ΔV must also have been halved.

A. Potential difference was halved.