- #1

- 138

- 0

## Homework Statement

Ok I am really confused!

Sometimes we use u=qv to find the potential energy

and sometimes u=0.5qv

Which one is correct?

## Homework Equations

u= electro static potential energy

v= voltage

q is charge

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- Thread starter sonutulsiani
- Start date

- #1

- 138

- 0

Ok I am really confused!

Sometimes we use u=qv to find the potential energy

and sometimes u=0.5qv

Which one is correct?

u= electro static potential energy

v= voltage

q is charge

- #2

- 674

- 2

U=qV is used for a charge (q) in an electrostatic potential (V). "U" is then the electric potential energy the charge has in that field.

I am not sure about U= 0.5qV, since that is very vague. If you can give an example where it is used, then you might be able to narrow it down.

- #3

- 138

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like for energy in a capacitor its used

- #4

- 674

- 2

- #5

- 138

- 0

and electrostatic potential energy is u=1/2qv. What is the difference between them other than the word 'electrostatic'

- #6

- 674

- 2

For your U = 1/2 qV, you must be reading about capacitance and the stored energy in the electric field of the charges. They are both different, and shouldn't get them too confused from a question you might be asked.

- #7

- 1

- 0

for those who gave the example of capacitors:

u = 0.5 c v^2

- #8

- 26

- 0

## Homework Statement

Ok I am really confused!

Sometimes we use u=qv to find the potential energy

and sometimes u=0.5qv

Which one is correct?

I will try to sharp two eqn above based on common textbook,

1) [tex]W = q . [V(a) - V(b)][/tex]

this eqn tells us for the work done to move a charge from point (a) to point (b). V here means potential difference between points (a) and (b).

2) [tex]W = \frac{1}{2}\Sigma^{n}_{i=1} q_i V(r_i)[/tex]

this eqn tells about work it takes to assemble a configuration of point charge. so W here represents energy stored in the configuration. factor 1/2 here is used to restore the eqn that initially count twice. (if you confused what I mean, you can check for yourself the derivation of this eqn). this eqn is more about the energy of a point charge distribution.

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