Answer:
Q: remains the same
C: decreases
ΔV: increases
Explanation:
When the capacitor is disconnected from the battery, and the wire connected to the plates are not touching anything else, it means that the charge cannot flow out from the capacitor: so, the charge stored on the plates of the capacitor, Q, will not change, regardless of the distance between the plates.
The capacitance of a parallel plate is given by
[tex]C=\frac{\epsilon_0 A}{d}[/tex]
where A is the area of the plates and d the separation between the plates. As we see from the formula, C is inversely proportional to d: so, if the plates are pulled apart to a larger separation, it means that d increases, and so C decreases.
Finally, the voltage across the capacitor is given by
[tex]\Delta V=\frac{Q}{C}[/tex]
and since we said that Q does not change while C decreases, it means that [tex]\Delta V[/tex] increases, since [tex]\Delta V[/tex] is inversely proportional to C.
