It means that the potential difference between the metal can and the little button on top of the battery is about 1.5 volts.
That's strictly the result of the chemicals in the battery, and has nothing to do with its size. If a battery as big as a house has the same chemistry inside that the AA has, the big one will also have 1.5 volts between its terminals. (But it'll run your flashlight much longer than the AA will, before it runs down.)
Answer:

Explanation:
Consider the axis diagram attached.
Given:
Ey = Ez = 0
Eₓ = - 4x N/C · m
Since electric field is in x direction, potential difference would be:
Here we integrate between limits 0 and 4.40 which is distance between A and B along x-axis.
![V_{b} - V_{a} = -4 \left[\begin{array}{ccc}\frac{x^{2} }{2} \end{array}\right]^{4.40}_{0}](https://tex.z-dn.net/?f=V_%7Bb%7D%20-%20V_%7Ba%7D%20%3D%20-4%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D%5Cfrac%7Bx%5E%7B2%7D%20%7D%7B2%7D%20%5Cend%7Barray%7D%5Cright%5D%5E%7B4.40%7D_%7B0%7D)

<span>Uniform. A parallel plate capacitor is a simple arrangement of electrodes and dielectric to form a capacitor. Here two parallel conductive plates are used as electrodes with a medium or dielectric in between them. Charge separation in a parallel-plate capacitor causes an internal electric field, which is uniform.</span>