Question

The charged plates of a capacitor attract each other, so to pull the plates farther apart requires work by some external force. What becomes of the energy added by this work? Explain.

Short answer

The required work done is stored as energy in the capacitor

This energy is stored as electrostatic potential energy in the plates.

Step-by-step solution

About Capacitance Potential Energy

Using the equations for charge-potential difference relation on capacitance and the formula of capacitance, one can find the effect made when a certain parameter is changed.

:Determine the Energy stored

Given

We do work to keep the two plates separated.

Explanation

The energy stored in the capacitor is given by

When we pull the plates, the distance between both plates increases and as the capacitance is inversely proportional to the distance as shown in equation (2), the capacitance decreases

As shown by equation (1), the energy stored will increase as the capacitance decreases when theseparateddistance increases. Therefore there is an increase in energy, this increase represents the work done is stored as energy in the capacitor.

Therefore The required work done is stored as energy in the capacitor