n:- a). The electrical force on a charge is related to the electric field ( caused by other charge ) by the equation Just like gravitational force , the static electrical force is a conservative force .this MEANS that the WORK done by the static electric force around any closed path is zero HENCE we have In the other , the intergral of the static electric field around a closed path is zero what about the integral of the magnetic field around closed path? that is we want to determine the value of Hence we have to be careful .the quantity B. d I doesn't represent some physical quantity and certainly not work . ALTHOUGH the static magnetic force does no work on a moving charge , we cannot conclude that the path integral of the magnetic field around a closed path is zero . we are just curious about what this analogous line integral amounts to .This is known as Ampere circuital lawb ) Ohm law in vector form The vector form of Ohm’s law is used in electromagnetics and material science. The vector form is given as,J = σ EWhere,– REPRESENTS vectorJ is the current density,Eis the electric field and σ is conductivity.