$$

Period:

Date

$q,$

parallel$-$plate capacitor is isolated with a charge $+-Q$ on each plate $(10$ points total$)$

If the separation of the plates is halved and a diecicuric $($constant $=5)$ is inserted in place of air,

by what factor does the energy storage change? $(5$ points$)$

$C{v}^2$

$\{\begin{array}{ccc}\text{:}\frac{1}{1}\frac{10}{1}& or& \frac{5}{\frac{1}{2}}\end{array}$

By what factor does the electric field between the plates change compared with the original value? $(5$ points$)$

$E=\frac{E}{a}$