this is where energy is lost n electric potential which is externaly maintained maintains the flow of charge widout

 

 

A                       B

+                        -

considerin ab to be a conductor direction of field is a TO b

but current wont flow (i.e. e- wont flow frm B to A unless there is external circuit connectin a nd b ( and electrons ll return to B aftr flowin to A thru an external circuit