where Ecs is the conservative electrostatic field created by the charge separation associated with the emf, dℓ is an element of the path from terminal "A" to terminal "B", and ‘·’ denotes the vector dot product. This equation applies only to locations "A" and "B" that are terminals, and (the electromotive force only exists within the bounds of the source) to paths between points "A" and "B" with portions outside the source of emf. This equation involves the electrostatic electric field due to charge separation Ecs and does not involve (for example) any non-conservative component of electric field due to Faraday's law of induction.