Electricity and Magnetism
# Circuit Behavior

Find $V_A$ in volts.

$\epsilon=2.1$ and resistivity $\rho=1.4 \times 10^{13}~\Omega \cdot \mbox{m}$. The capacitor is charged by connecting it to a voltage source. How long will it take **in seconds** for the capacitor to lose half of the charge acquired after disconnecting it from the source?

A 120V source is connected across the plates of a parallel-plate capacitor. The capacitor is being submerged vertically at constant speed into a container filled with water. What current **in Amps** flows through the voltage source during this process if it takes $\tau=20 s$ to totally submerge the capacitor? The capacitance (in air) of the capacitor is $C_{0}=12\mu F$ and water's relative permittivity is
$\epsilon=81.$

Hint: If the capacitor is partially submerged at an instant of time try figuring out how to treat it as two separate capacitors at that instant.