Difference Between EMF and Potential

The major difference between EMF and potential is The electromotive force represents the energy supplied per unit of charge, while potential difference denotes the energy consumed by a single coulomb of charge.

What is EMF?

EMF, or electromotive force, denotes the electrical potential difference originating from an energy source like a battery. Michael Faraday’s principle asserts that fluctuating magnetic fields can also induce EMF, a voltage measured in volts (V), crucial for creating a potential difference and propelling current in an electric circuit.

It operates akin to a charge pump. As per Kirchhoff’s second law, in an EMF-driven circuit, the total potential drops equate to the EMF. Various devices, including solar cells, fuel cells, and thermocouples, serve as EMF generators, harnessing electrochemical energies, similar to batteries.

What is Potential?

Potential, present in electric, magnetic, and gravitational fields, is location-dependent. The potential difference between points A and B is determined by subtracting A’s potential from B’s. This difference signifies the work needed to move a unit mass or charge from B to A. Gravitational potential difference is measured in J/kg, while electric potential difference is measured in volts. In electrical circuits, current flows from higher to lower potential. Despite its broader usage, “potential difference” is commonly associated with electrical contexts, requiring caution to prevent misunderstandings.

EMF vs Potential

The major difference between EMF and potential is that:

AspectEMF (Electromotive Force)Potential (Voltage)
DefinitionThe energy per unit charge supplied by a source.The work done per unit charge moving between points in an electric circuit.
UnitsVolt (V)Volt (V)
RepresentationE = IRV = IR
NatureScalar quantity.Scalar quantity.
UsageAssociated with a power source (e.g., battery).Used to describe the energy difference between two points in a circuit.
Loop Rule in CircuitsEMF is considered in loop rule equations.Potential is used in loop rule equations.

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