3 ms·
Adding the second capacitor is equivalent doubling the area of a single capacitor. If you had a plate capacitor where the plates were extendable you could charg
by mdturnerphys 6y ago
Adding the second capacitor is equivalent doubling the area of a single capacitor. If you had a plate capacitor where the plates were extendable you could charge it and decrease the energy by extending the plates, which tells you that there's a force that is pushing to extend the plates. Of course there is--the charges on one plate repel each other and "want" to increase their spacing. If you do extend the plates there is a force times a distance, which equals work done by the charges, decreasing the capacitive energy.
- compumike 6y agoThis is a beautiful explanation, thank you! It's also compatible with barbegal's hydraulic pressure analogy elsewhere in the discussion. A liquid- or gas-filled tank feels pressure (i.e. force per area) on the walls as the fluid "wants" to either (1) flow to a lower gravitational potential energy location, for a liquid tank in a gravitational field, or (2) expand in volume, in the case of a pressurized gas tank.