# Difference between EMF and Voltage

**URL:** <https://forumautomation.com/t/difference-between-emf-and-voltage/14507>\
**Category:** Electrical\
**Tags:** interviewquestions\
**Created:** [October 15, 2026, 3:57pm UTC](https://forumautomation.com/t/difference-between-emf-and-voltage/14507 "2026-10-15T15:57:24Z")\
**Posts on this page:** 1\
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**Author:** ![Rabert](https://forumautomation.com/user_avatar/forumautomation.com/rabert/32/6784_2.png) [@Rabert](https://forumautomation.com/u/Rabert)\
**Post date:** [October 15, 2026, 3:57pm UTC](https://forumautomation.com/t/difference-between-emf-and-voltage/14507/1 "2026-10-15T15:57:24Z")

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## Difference between EMF and Voltage

**[EMF (Electromotive Force)](https://forumelectrical.com/basic-electrical-terms-and-definitions/)** and voltage are both measured in volts (V), but they represent different electrical concepts.

 ![1](https://cdn.forumautomation.com/original/2X/6/696d2277fdce30a5d10380eb895cd0ea6220bd7e.jpeg)

EMF is the energy supplied by a source per unit charge while voltage is the electrical potential difference between two points in a circuit.

| **Feature** | **EMF (Electromotive Force)** | **Voltage** |
| --- | --- | --- |
| Definition | Energy supplied per unit charge by an electrical source | Electrical potential difference between two points |
| Symbol | E or ε | V |
| Unit | Volt (V) | Volt (V) |
| Main Function | Drives electric charge around a circuit | Represents the potential difference that can drive current |
| Measurement | Measured across a source under open-circuit conditions to determine its EMF | Measured between two points in a circuit |
| Under Load | Can differ from terminal voltage due to internal resistance | May decrease across a source’s terminals when current flows |
| Example | EMF generated by a battery or generator | Voltage across a resistor, lamp, or battery terminals |