The capacitor was charged. Without disconnecting from the batteries, the distance between the plates was doubled.

The capacitor was charged. Without disconnecting from the batteries, the distance between the plates was doubled. How many times have the electrical capacity and potential difference changed?

The capacitance of the capacitor C is calculated by the formula:
C = e₀eS / d,
where e₀ is the electric constant,
e is the dielectric constant of the medium,
S is the area of the plates.

When the distance changes by half, the capacitance of the capacitor will decrease to the value C₁ = e₀eS / 2d, that is, by half.
Since the source from the capacitor was not disconnected, the potential difference will not change.

Answer: The electrical capacity has decreased by 2 times, the voltage has not changed.