A scientist is conducting an experiment with two parallel plates separated by a distance of 7 millimeters, charging one plate positively and the other negatively. She observes the current flowing through the circuit. If she decides to increase the distance between the plates to 14 millimeters, what will likely happen to the electric field strength and the current flow in the circuit?

If the scientist keeps the same voltage on the plates, the electric field between them will drop roughly in half when the separation is doubled from 7 mm to 14 mm, because the field is inversely proportional to distance. A weaker field means fewer free electrons are pulled from the air or any conducting material, so the ionization that drives current will be reduced. Consequently the current flowing through the circuit will drop, often sharply, because the medium’s conductivity has fallen. For example, a 1 kV potential difference gives about 1. 4 × 10⁵ V/m at 7 mm, but only 7 × 10⁴ V/m at 14 mm, leading to a noticeably lower current.