| p{3cm} p{3cm} p{3cm}} (1) $50$ | (2) $64$ | (3) $80$ | (4) $96$ |
\textbf{178.} By partially discharging an electric capacitor, the potential difference across it decreases by 80 percent. The energy of this capacitor decreases by what percent?
\medskip
\begin{tabular}{p{3cm} p{3cm} p{3cm} p{3cm}}
(1) $50$ & (2) $64$ & (3) $80$ & (4) $96$
\end{tabular}
\medskip