Thursday, August 6, 2015

electromagnetism - What is Electromotive force (EMF)? How is it related to potential difference?


What is Electromotive force (EMF)? How is it related to the potential difference? Is it created by the potential difference in any conductor? Is it a process? Why is it called force?



Does writing EMF instead of voltage make any difference in AC circuits? (Studying alternating current I found some books using EMF while others used voltage.)



Answer



I dislike the term EMF (Electromotive force) as it is very confusing.



Electromotive force, also called emf (denoted $\mathcal{E}$ and measured in volts), is the voltage developed by any source of electrical energy such as a battery or dynamo.



Which means that all EMF are voltages but not all voltages are EMF. A voltage is only an EMF if it is a source of energy.


Kind of like the distinction between luminescent light (from a light bulb) and reflected light (from your desk) if you measure it there is no physical measurable difference. The only difference is that one is a source and the other is not.


No comments:

Post a Comment

classical mechanics - Moment of a force about a given axis (Torque) - Scalar or vectorial?

I am studying Statics and saw that: The moment of a force about a given axis (or Torque) is defined by the equation: $M_X = (\vec r \times \...