# Symboling Voltage

1. Aug 29, 2006

### Line

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?

2. Aug 29, 2006

### Staff: Mentor

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

3. Aug 29, 2006

### Line

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

4. Aug 30, 2006

### Staff: Mentor

Sounds like your book has problems. What are the title and author of the book? Potential difference is voltage V, and $$E = - \nabla V$$

5. Aug 30, 2006

### Valhalla

E can be used for electromotive force which is equivalent to voltage right?

Last edited: Aug 30, 2006
6. Aug 30, 2006

### Averagesupernova

Picture this:
-
E = 10V
I = 10A
-
Understand?

7. Aug 30, 2006

### Line

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

Last edited: Aug 30, 2006
8. Aug 31, 2006

### a4swe

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).

9. Aug 31, 2006

### Staff: Mentor

Holy smokes, that's totally wrong and misleading. Try putting units into that equation....:grumpy:

10. Sep 1, 2006

### Line

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

11. Sep 1, 2006

### Staff: Mentor

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.

Last edited: Sep 1, 2006
12. Sep 1, 2006

### Line

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

13. Sep 1, 2006

### Ouabache

You are correct, E can be used for electromotive force (EMF), and virtually synonymous with voltage. For a more detailed description of electromotive force, follow this link.

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.

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

Last edited: Sep 1, 2006
14. Sep 4, 2006

### leright

Sounds to me you have a terrible book, Line.