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# What is an equipotential? watch

1. (Original post by Mathemagician)
no, he is talking about electric field strength and not electric potential
nope, he says "So when distance from the conducting sphere doubles the electric potential falls by a factor of 4?"

which was wrong.
2. (Original post by Revenged)
Nope it's an inverse square law

V = kQ/r
but V = kQ/r is not inverse SQUARE.. its just inverse.
3. but the formula was right, E = kQ/r^2
4. So, the electric potential tells you the potential difference at one point in a electric field but could you use this following formula in both the situations?

V = kQ/r
5. (Original post by Revenged)
So, the electric potential tells you the potential difference at one point in a electric field but could you use this following formula in both the situations?

V = kQ/r
it is analogous to gravitational potential.
6. (Original post by Revenged)
So, the electric potential tells you the potential difference at one point in a electric field but could you use this following formula in both the situations?

V = kQ/r
that is if you have a charged sphere for example while if you want to find the electrical potential between two conducting parrallel plates you use Ex=V
7. (Original post by mik1w)
but the formula was right, E = kQ/r^2
this is the electrical field strength,so when distance doubles the electrical field strenth decreases by the factor of 1/4
while for electrical potential which is V you know so that V=KQ/r so that when the distance is doubled the electrical potential halves though I don't think that this equation is requierd from us hmmm. also the electrical potential energy=KQq/r
8. (Original post by habosh)
this is the electrical field strength,so when distance doubles the electrical field strenth decreases by the factor of 1/4
while for electrical potential which is V you know so that V=KQ/r so that when the distance is doubled the electrical potential halves though I don't think that this equation is requierd from us hmmm. also the electrical potential energy=KQq/r
yeah. It is required for OCR B though.
9. and equipotential lines,are lines where there is no change in the energy.the energy along them is constant and they are perpendicular to the field lines
10. ummm! sorry yes it is
11. ok... so

For a parallel plates

E = V/d

therefore if i rearrange that to

V = Ed (i get what you have)

For a conducting sphere, however,

V = kQ/r
E = kQ/r^2

Is that right?
12. (Original post by Mathemagician)
yeah. It is required for OCR B though.
also the transformer thingie..to drow flux graphs...etc
13. (Original post by Revenged)
ok... so

For a parallel plates

E = V/d

therefore if i rearrange that to

V = Ed (i get what you have)

For a conducting sphere, however,

V = kQ/r
E = kQ/r^2

Is that right?
yep...sure it's for a conducting other wise we wont have an electrical field at all
14. 'electrical potential energy=KQq/r'

What's that?

Looks like Newton's Law of something
15. for 2 spheres, what is the electric field strength and the electric potential?

edit: what are the formulae?
16. (Original post by Revenged)
'electrical potential energy=KQq/r'

What's that?

Looks like Newton's Law of something
yeah, its similar to Newtons law of gravitation.
17. electric potential? it's to work out electric field strength?
18. (Original post by Revenged)
'electrical potential energy=KQq/r'

What's that?

Looks like Newton's Law of something
yeah,this is not requierd from edexcel though dont panic for example
F(electrical)=KQq/r^2
right?
now the work done=electrical pontential enegry
so W=Fx=PEe
so
as x=r then
Fr=KQqr/r^2
so then the r/r^2=1/r
so KQq/r=Pe
19. (Original post by habosh)
this is the electrical field strength,so when distance doubles the electrical field strenth decreases by the factor of 1/4
while for electrical potential which is V you know so that V=KQ/r so that when the distance is doubled the electrical potential halves though I don't think that this equation is requierd from us hmmm. also the electrical potential energy=KQq/r
no lowercase q there, V=kQ/r
20. (Original post by mik1w)
no lowercase q there, V=kQ/r
no that was the electrical potential energy not the electrical potential
PE=KqQ/r
and V=QK/r

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