Let’s consider a capacitor formed f

Let’s consider a capacitor formed from a pair of parallel plates as shown in Figure
26.2. Each plate is connected to one terminal of a battery, which acts as a source of
potential difference. If the capacitor is initially uncharged, the battery establishes
an electric field in the connecting wires when the connections are made. Let’s focus
on the plate connected to the negative terminal of the battery. The electric field in
the wire applies a force on electrons in the wire immediately outside this plate; this
force causes the electrons to move onto the plate. The movement continues until
the plate, the wire, and the terminal are all at the same electric potential. Once this
equilibrium situation is attained, a potential difference no longer exists between
the terminal and the plate; as a result, no electric field is present in the wire and
the electrons stop moving. The plate now carries a negative charge. A similar process
occurs at the other capacitor plate, where electrons move from the plate to the
wire, leaving the plate positively charged. In this final configuration, the potential
difference across the capacitor plates is the same as that between the terminals of
the battery.