PDA

View Full Version : Symboling Voltage


Line
Aug29-06, 04:31 PM
Throughout EE I've seen many symbols. When it comes to voltage I've seen E,V,and e. Do they all mean the same thing?

berkeman
Aug29-06, 04:38 PM
E is generally used for electric field

V or v is generally used for voltage

e generally refers to an electron or the constant from natural logs

Line
Aug29-06, 09:04 PM
In the book I've been readinf E means potential difference.

And e was in one about Industion. Eqaution looked something like
L=de/dt

berkeman
Aug30-06, 10:39 AM
Sounds like your book has problems. What are the title and author of the book? Potential difference is voltage V, and E = - \nabla V

Valhalla
Aug30-06, 11:49 AM
E can be used for electromotive force which is equivalent to voltage right?

Averagesupernova
Aug30-06, 03:19 PM
Picture this:
-
E = 10V
I = 10A
-
Understand?

Line
Aug30-06, 07:18 PM
Sounds like your book has problems. What are the title and author of the book? Potential difference is voltage V, and E = - \nabla V

If you're counting V is the actual voltage and Eis the voltage with ground
calculated then E=V- \nabla V ............potential difference.

a4swe
Aug31-06, 05:46 AM
Here we use U for the voltage and sometimes E for the EMK.
We use V to symbolize the potential difference.
e should be the time dependant voltage (of course we use u for that).

berkeman
Aug31-06, 08:40 AM
If you're counting V is the actual voltage and Eis the voltage with ground
calculated then E=V- \nabla V ............potential difference.
Holy smokes, that's totally wrong and misleading. Try putting units into that equation....:grumpy:

Line
Sep1-06, 12:05 AM
Holy smokes, that's totally wrong and misleading. Try putting units into that equation....:grumpy:
Potential DIfference does eqaul voltage minus the change in voltage doesn't it?

IN my boo E was potential difference, V was voltage and e had to do with induction.

e=N x d(webers)/dt

berkeman
Sep1-06, 09:38 AM
Potential DIfference does eqaul voltage minus the change in voltage doesn't it?
It can, but that's not what you wrote. There's a big difference between \nabla and \Delta :rofl:

FYI, \Delta can represent a change (as I guess you intended), but \nabla is the gradient operator. So the equation E = -\nabla V is the way that we usually show the relationship between the vector electric field E and the scalar potential V.

Line
Sep1-06, 07:50 PM
In the beginning of the book they teach us E as the voltage.

I=E/R

Then in the middle they give us V.

P=VV/R

Ouabache
Sep1-06, 11:26 PM
E can be used for electromotive force which is equivalent to voltage right?
You are correct, E can be used for electromotive force (http://www.phys.ualberta.ca/~gingrich/phys395/notes/node8.html) (EMF), and virtually synonymous with voltage. For a more detailed description of electromotive force, follow this link (http://en.wikipedia.org/wiki/Electromotive_force).

As Berkeman has also mentioned, E (especially boldface) is also used in electrical engineering for "electric field", so be careful of the context in which you are using these symbols.


In the beginning of the book they teach us E as the voltage.

I=E/R

Then in the middle they give us V.

P=VV/R

So in your book, they are using E interchangably with V for voltage potential. (they are virtually synonymous).

leright
Sep4-06, 04:54 PM
Sounds to me you have a terrible book, Line.