Definition
A vector field F on a region is conservative when there exists a scalar potential φ such that F equals the vector of partial derivatives of φ; equivalently, line integrals of F depend only on endpoints and not on path within the region.
Principle
Principle
Conservativity characterizes exact differential vector fields whose circulation along closed loops vanishes on simply connected domains, reflecting that local differentials integrate to a global potential.
Demonstration
Demonstration
In electrostatics in a static region, the electric field (neglecting time variation) is conservative: it is given by the spatial derivative of an electrostatic potential and its line integral between two points is path independent.
Misapplication
Misapplication
Concluding a field is conservative from the local condition curl F = 0 without checking domain topology: curl-free does not imply a global potential on domains with holes or nontrivial topology.
Consequence
Consequence
Correct identification yields a scalar potential, path-independent work calculations, and simplifications of boundary-value problems by reducing vector equations to a scalar equation for the potential.
Reversal
Reversal
A non-conservative (rotational) field, where circulation around closed loops may be nonzero and work depends on the path, such as the Lorentz force from a magnetic field on a moving charge.
Boundary
Boundary
Requires sufficient smoothness and consideration of domain connectivity; in regions that are not simply connected additional tests are needed and some curl-free fields may fail to be conservative globally.
Semantic Tension
Semantic Tension
Conservative versus irrotational: 'irrotational' often denotes local vanishing of curl, while 'conservative' requires the existence of a global potential; the two coincide under appropriate topological hypotheses.
Synthesis
Synthesis
A conservative vector field is an exact differential field that globally arises from a scalar potential so that integrals depend only on endpoints and closed-loop circulation vanishes in the permitted domain.