A parallel-plate capacitor has a potential energy due to its charge of 6.00 mJ.It is accidentally filled with water in such a way as not to discharge its plates.How much energy does it continue to store after it is filled? (The dielectric constant for water is 78 and for air is 1.0006. )

Question

Quizplus · Accepted Answer

The energy stored in a capacitor is inversely proportional to the dielectric constant. When the capacitor is filled with water, the dielectric constant increases from 1.0006 to 78, reducing the energy stored by a factor of 78. Therefore, the new energy is 6.00 mJ / 78 ≈ 0.077 mJ.

A Parallel-Plate Capacitor Has a Potential Energy Due to Its