about emf and voltage


Joined Nov 17, 2003
I am now able to conclude the discussion as:The emf is same as voltage but it is used in difeferent sense.Thy have same units and we must not confuse both terms.We should have a mind-set like a voltmeter (because it views both as same and equally measures them).Am I right?
Yes. My advice would be to ignore EMF and talk about voltage and potential difference in the general sense, and a voltage source when talking about a source device such as a battery etc.

By that logic... would mass be energy? - measured in Joules per square V?

E = 1/2 MV^2 ergo M = 1/2 E / V^2
Indeed so, something Einstein came to realise. Incidentally Einstein's work on the equivalence can be directly derived from Maxwell's Equation which were published some 40-years earlier. Maxwell's Equations truly are a magnificent piece of science and intuition.



Joined May 19, 2004
you've been provided much good information, and it seems to be a matter of symantics. the "quantity" (e.g. length, weight, speed, etc. ) is emf. electro-motive force is that force needed to move electrons. the "unit of measure" for the quantity is the volt. the voltage (synonym potential)then would be the amount of volts.


Joined Apr 2, 2007
Voltage sources are called so because they provide rated voltages at any load.
the same is not true for power hence rating a source in terms of power is going to be difficult.
of course m/c like generators are rated for max power in terms of VA but that is due to metallurgical limitations.