Question

how much work is done in moving a charge of across two points having a potential difference of 12 volt

Answer 1

The difference in potential causes the charge to flow.

Furthermore, the Workdone(W) on the charge(of magnitude q) to move it against the field is Potential difference(V),

i.e, V=W/q

Now, the potential difference maintained is 12V, the only factor upon which the work depends is the magnitude of the charge, say q be the charge of that particle, then work done by the knowledge of potential difference,

W = 12(q)