(II) In a dynamic random access memory (DRAM) computer chip, each memory cell
chiefly consists of a capacitor for charge storage. Each of these cells
represents a single binary-bit value of 1 when its 35 -fF capacitor \(\left(1
\mathrm{fF}=10^{-15} \mathrm{F}\right)\) is charged at \(1.5 \mathrm{V},\) or 0
when uncharged at 0.V. (a) When it is fully charged, how many excess electrons
are on a cell capacitor's negative plate? (b) After charge has been placed on
a cell capacitor's plate, it slowly "leaks" off (through a variety of
mechanisms) at a constant rate of 0.30 \(\mathrm{fC} / \mathrm{s}\) . How long
does it take for the potential difference across this capacitor to decrease by
1.0\(\%\) from its fully charged value? (Because of this leakage effect, the
charge on a DRAM capacitor is "refreshed" many times per second.)