Coulumbs, Joules and their relation in electronics

[Tryp]

Hello,
I'm bit confused about relation of the two, would be really great if someone explained it.
So the coulumb is said to be the force between two charges(repelling or attracting), which depends
on quantity of charges and their distance.
Joule is said to be force that is needed to move object of 1kg by 1 metre in second

So, electric current , for example, 1 Ampere, is when 1 Coulumb travels from point A to point B in 1 second, which is coulumbs per second (C/s)

One Volt, is how many Joules one Coulumb transfers(J/C). Here I don't understand
how exactly force between charges transfers energy needed for work ?

And last thing is resistance in electricity - By Ohms law R= V/I,
in other terms that is

````J
```---
````C
-----------
````C
```---
````S

and that equals to J*S ( I tried using math symbols but the code is messing it up)

So basically resistance in electric circuit is how much joules it does not let thru every second?

I'm confused.

 

[Naty1]

I suggest you do some basic reading, for each of the terms confusing you, but maybe I can clear up parts. After a while they'll make sense but you have to take time at first to read and think about each...and their relationship.

Coulomb is a quantity of charge; a moving charge constitutes a current.

for q = it, q coulombs, i current and t time.

A joule is a unit of work...one Newton meter where a Newton is a unit of force...a mechanical view is
W = Fd, w is work, F is force and d distance.

and an electrical perspective:

In P = IE = I<sup>2R = E2/R are versions of Joule's law in volt-amps, joules/sec and/or watts.

Power, as you can see, is work per unit time...the rate at which work is done.</sup>

 

[mburt]

I always parallel (pardon the pun) current with speed. Current is C/s, whereas speed is m/s (easy concept). Current is just how much charge moves through a wire per unit of time.

Voltage always tend to be a harder concept. My teacher attempted to explain it as compared to pressure in a water pipe, however I'm not sure I entirely agree with it (but I'll reserve further judgement).

Voltage of course is J/C, which is a Nm/C... So it's just amount of "work" produced in ratio with the charge of the wire.

It's a tough concept, but I found as I worked with these units more and more my understanding of them improved with time.

As for resistance the units don't help much (Js/C^2), but basically I think of it as the back-force on the current (like resistors along the path)

 

[Tryp]

Thanks guys, that made things a bit clear.

Voltage always tend to be a harder concept. My teacher attempted to explain it as compared to pressure in a water pipe, however I'm not sure I entirely agree with it (but I'll reserve further judgement).

Yeah I have heard it too, that it's like if there's pipe filled with water and you add, say, 1 litre to one end, you will also get 1 litre out of the other end, but if there's load or resistance, the energy that was added will be absorbed by it...something like that.

 

[Tryp]

In P = IE = I<sup>2R = E2/R are versions of Joule's law in volt-amps, joules/sec and/or watts.</sup>

<sup>E is energy or Joule in other words?</sup>