- #1
devious_
- 312
- 3
I need help understanding electric fields. I basically suck at answering questions related to them (I get 95% of them wrong
).
What I do know about them is:
The electric field vector moves from a positive charge (+q) to a negative charge (-q). (Is this the same case in a capacitor? I saw the vector pointing for -q to q through the dielectric of two plates.)
I also know a few equations:
[tex]E=\frac{F}{q}=k\frac{Q}{r²}[/tex]
[tex]\Delta U_{e} = -\Delta W_e = - Fd = -Eqr[/tex]
[tex]W = kqQ (\frac{r_{a}-r_{b}}{r_{a}r_{b}})[/tex]
[tex]\Delta U_{e} = k\frac{qQ}{r}[/tex]
[tex]\Delta V = \Delta \frac{U_{e}}{q} = k\frac{Q}{r}[/tex]
[tex]\Delta V = \frac{\Delta W_{e}}{q} = \frac{Fd}{q} = \frac{Eq}{q}d = Ed[/tex]
[tex]\Delta V = \frac{q}{C}[/tex]
[tex]C = \frac{\epsilon_{0}A}{d}[/tex]
I appologize if this is the wrong forum.
![Cry :cry: :cry:](/styles/physicsforums/xenforo/smilies/cry.png)
What I do know about them is:
The electric field vector moves from a positive charge (+q) to a negative charge (-q). (Is this the same case in a capacitor? I saw the vector pointing for -q to q through the dielectric of two plates.)
I also know a few equations:
[tex]E=\frac{F}{q}=k\frac{Q}{r²}[/tex]
[tex]\Delta U_{e} = -\Delta W_e = - Fd = -Eqr[/tex]
[tex]W = kqQ (\frac{r_{a}-r_{b}}{r_{a}r_{b}})[/tex]
[tex]\Delta U_{e} = k\frac{qQ}{r}[/tex]
[tex]\Delta V = \Delta \frac{U_{e}}{q} = k\frac{Q}{r}[/tex]
[tex]\Delta V = \frac{\Delta W_{e}}{q} = \frac{Fd}{q} = \frac{Eq}{q}d = Ed[/tex]
[tex]\Delta V = \frac{q}{C}[/tex]
[tex]C = \frac{\epsilon_{0}A}{d}[/tex]
I appologize if this is the wrong forum.