Name a device that can be used to maintain a potential difference across a conductor. Also,draw its circuit symbol.

(N/A) device that maintains a potential difference across a conductor is called a cell or a battery.
The circuit symbol for a cell consists of two parallel vertical lines,where the longer line represents the positive terminal $(+)$ and the shorter,thicker line represents the negative terminal $(-)$.
Circuit symbol for a cell:
$| |$ (Longer line: $+$,Shorter line: $-$)