Question

Is emf equal to potential difference?

Answer 1

Electromotive force (emf) and potential difference are related but not exactly the same thing.

1. Electromotive Force (emf):
   

   - Emf is the energy provided by a source (like a battery or generator) to move charge through a circuit.
   - It is the driving force that causes current to flow in a circuit.
   - Emf is measured in volts and is associated with the energy per unit charge supplied by the source.

1. Potential Difference:
   

   - Potential difference, also called voltage, is the difference in electric potential between two points in a circuit.
   - It tells you how much energy is required to move a unit charge between those two points.
   - It is also measured in volts.

Key Difference:

1. Emf refers to the energy supplied by a power source (like a battery or generator) to move charge around the circuit.
   

1. Potential difference refers to the energy lost or gained by the charge as it moves through components in the circuit (like resistors).
   

In a simple circuit, the emf of the power source is the potential difference across the terminals of the source when no current is flowing. However, when current flows, the potential difference across the source (emf) might be different from the potential difference across other components in the circuit due to energy losses (like resistance in wires).

So, emf is the total energy supply capability, while potential difference is the energy change per unit charge between two points.