# I cant understand voltage

1. Feb 18, 2009

### Ant92

I'm doing AS-level physics at the moment and we have moved onto circuits, current, etc. I feel a bit of an idiot but i cannot seem to describe in fully what voltage is. this is mainly because i dont really know. i understand that it represents the potential difference in a circuit, but i have limited understanding of that too. i can remember equations etc, regarding voltage, (V=IR, V=P/I, etc), i just cannot explain it if a question asks me too. any help would be appreciated.

thank you

My try at explaining it

It has some thing to do with the pd of a circuit which when all the the pd across a circuit is combined it is the same as the electromotive force provided by the power cell

2. Feb 18, 2009

### Kruum

If you can understand what gravitational potential is you can then understand what electrical potential is. Let's say you want to lift an object of mass $$m$$ to height $$h$$. Now when you start to lift the object, gravitation starts to pull it down. If you want to beat the gravitiy you must do certain amount of work to get $$m$$ to $$h$$.

Now electric potential is basically the same but the gravitation can change directions depending on the particles's charge. Now you have to plates one of them has a charge of $$Q$$ and the other $$-Q$$ and their distance is $$h$$. If you want to move a particle $$q$$ from $$-Q$$ to $$Q$$, you need to do certain amount of work. $$q$$ is positively charged.

Does that help?

3. Feb 18, 2009

### Ant92

so are you saying that the potential difference, (i.e. voltage), is the potential energy that will be needed to move a charged carrier to different points around a circuit?

4. Feb 18, 2009

### sirchasm

Yup, voltage = charge potential. And charge is polarized already, which comes in handy.

5. Feb 18, 2009

### Ant92

thankyou

6. Feb 18, 2009

### tiny-tim

voltage = energy per charge

Hi v!

All the electric units are connected to each other and to ordinary units …

for example 1 volt = 1 joule per coulomb …

voltage = energy per charge …

in other words, the voltage between two points tells you how much energy you get if you move a charge across.