Can u pls tell me sir ...wat is difference b/w potential n potential difference n wat is cross sectional area ????

Potential of a point is the energy required by a unit charge on moving from infinity to that point, where as potential difference between two points is the energy required by a unit charge on moving from one point to another.

 

cross sectional area is the area through which flow of some physical quantity like electric/magnetic field or some other quantity is considered.