Question

When a capacitor is charged, electrons flow from the battery terminal to the plate of the capacitor, as the electrons flow through the wire, they must be having some kinetic energy?

So, when the electrons finally stop at the plates of the capacitor, what happens to their kinetic energy? We don't normally assume the kinetic energy to get stored in the capacitor, we only consider the energy stored in the capacitor to be due to the decrease in potential energy of the charge as it flows from one terminal of battery to the other, then where does the kinetic energy go?

Answer 1

The kinetic energy of the electrons flowing into a capacitor is converted into heat and electrostatic potential energy stored in the electric field between the capacitor plates. This process is governed by Kirchhoff's second rule and results in energy storage useful for powering electronics.

Step-by-step explanation:

When electrons flow to the plate of a capacitor during charging, they initially have kinetic energy due to their motion through the circuit. However, as the capacitor reaches the same voltage as the battery, the electron flow ceases and there is no more kinetic energy.

he key point is that the kinetic energy of the electrons is not stored directly; rather, it is transformed into heat due to the resistance of the circuit's components (like wires and resistors) and into the electric field energy between the capacitor plates. The energy stored in a capacitor is electrostatic potential energy.

The energy storage process can be described using Kirchhoff's second rule, where the algebraic sum of changes in potential around any closed loop must be zero. When the capacitor is disconnected, it holds the energy that can then be used to power a device like a lightbulb.

This stored energy, which remains as an electric field in the absence of a battery, is why capacitors are used as temporary energy storage devices in electronic circuits.