I want to learn about electricity

[7ronin]

Let's summarize:

A volt is the basic unit of electrical potential or electromotive force. One volt is the force required to send one ampere of electrical current through a resistance of one ohm. The symbol for voltage is "E". [Some people use V instead of E]

An ampere or "amp" is the measure of electrical current flow. The symbol for amperage is "I".

An Ohm is the amount of resistance overcome by one volt in causing one ampere to flow. The Ohm measures resistance to current flow in electrical circuits. Some materials "conduct" electricity better than other materials. For example, gold is a better conductor than copper. Some materials, for example ceramics, are said to have an infinite resistance because they do not conduct electricity. Such materials are "insulators." Resistance is also affected by other factors. Let's say you have a six inch copper wire and a twelve inch copper wire. The resistance is going to be higher in the longer wire because there is more material that the electrical current must be "pushed" through.

The relationship between resistance (ohms), electrical potential (volts), and current (amps) is expressed in Ohms Law which says that voltage equals current divided by resistance. If you have ten amps of current and the total resistance in the electrical circuit is two ohms then the voltage of the circuit is five volts.

A watt is a measure of electrical power. The symbol for power in watts is "P". Power equals voltage (E) times current (I). In the above example where you have two volts and ten amps, the power produced is 20 Watts.

There are two types of current. Direct current (DC) which flows in one direction only and Alternating Current (AC) which constantly changes (alternates) the direction of current flow. Your house current is AC. The current in your cell phone is DC.

Current flows from an area of high potential (The positive terminal on a battery) to an area of low potential (the negative terminal on a battery).

 

[History_Buff]

7ronin is wrong on his equation, P=IV, so the Power produced in a 2-Volt, 10-Amp system is 20 Watts.

Other than that it's pretty sound though

 

[Narz]

So if I chant Ohm can I conduct electricity?

 

[Grisu]

So if I chant Ohm can I conduct electricity?

no, but you might be able to resist it

 

[Narz]

no, but you might be able to resist it

Maybe that's what those dudes who turn to God on death row are thinking.

 

[col]

Sign up for one of my classes, Narz. I'll expect to see you there in September.

 

[Panzeh]

If you want to learn about electricity, there's a power line in front of my house. Just write me into your will before you go.

 

[7ronin]

7ronin is wrong on his equation, P=IV, so the Power produced in a 2-Volt, 10-Amp system is 20 Watts.

Other than that it's pretty sound though

Thanks History Buff. I don't know what I was thinking. I've corrected my post.

When I was studying electricty the instructor told us that there was a third kind of current - FC. He said it stood for "F.....g Current," the kind that shocks you.

 

[IglooDame]

Electrical Engineering 101: "V=IR and derive the rest".

Not coincidentally, that professor was the most hated and feared man on the Academy grounds.

 

[betazed]

Electrical Engineering 101: "V=IR and derive the rest".

That's interesting. I can't imagine how you can describe (derive) tons of stuff in electrical engineering with just Ohm's law. Induction motors, transformers, solenoids etc. all come to mind.

 

[Sidhe]

Don't you just derive power from common sense? You know like if I have all the energy or "power in a circuit" I have the wattage value? So what gives me the total amount of electrons and their force? ah AmpasxVolts. Not rocket science.

I can't remember having to derive them, your teacher must of been a Nazi

It's interesting to note that the electromagnetic force equation is almost exactly the same as the gravitational force equation and is almost exactly the same as the weak force equation, that is they all appear equivalent but act differently at different energy levels, in other words electromagnetic and weak force and gravity all appear pretty simmilar only the energy state appears to effect their behaviour(one might even suggest they are all the same thing or unified, if you were very brave of course) but again I digress.

Remember g(f)=g(k)(m1,m2)/r^2

g(f)force of gravity
g(k)=gravitational constant
m1=mass1
m2=mass2
r=radius(distance between particles)

well stick electrons in there instead of the masses and play with the electrical charge signs and the electromagnetic constant and you have the force of electromagnetic repulsion or attraction. Fun huh.

Classical physics is very ordered and just so, it's elegant really.

 

[IglooDame]

That's interesting. I can't imagine how you can describe (derive) tons of stuff in electrical engineering with just Ohm's law. Induction motors, transformers, solenoids etc. all come to mind.

Right.

Did I mention that the professor was hated and feared?

 

[betazed]

Did I mention that the professor was hated and feared?

Ah! Now that makes sense.

 

[Narz]

Sign up for one of my classes, Narz. I'll expect to see you there in September.

I'll have to take it virtually.

 

[Masquerouge]

Now, there is a law of electricity called Ohm's Law which is the most fundamental relationship between these three quantities: current, resistance and voltage. The law is:

V=IR

Where V is voltage, I is current and R is resistance. Thus, the voltage drop over a resistor is the result of both its resistance and the amount of current passing through.
However, power can also be expressed in terms of electrical values:

P=IV

Where P is power, V is voltage and I is current. (This can be recombined with Ohm's Law to create three different expressions for power, all equivalent.) Thus, we express the amount of power an appliance uses as its current times the amount of voltage, or potential, lost as it passes through the appliance.


That's really basic electricity for you.

Ah! My formulas were correct! I still can remember stuff I never use! Vindication!

 

[Babbler]

I was going to say buy one of these and look it up yourself. But col beat me there, even with more smartassed comment.

But just the basics really. Ok, so there are watts and volts. What's the difference?

Watts is a general unit of energy (Joules) over time (seconds). Volts are units of electric potential, that is potential energy (Joules) over charge (Coulombs)

 

[Cheezy the Wiz]

nah it's easy I just thought you might be interested in the broader picture. you aughta see the Schrodinger Equation, one look at that and I want to give up physics forever.

http://scienceworld.wolfram.com/physics/SchroedingerEquation.html
Schrödinger Equation -- from Eric Weisstein's World of Physics

that's for working out the wave function of a single particle, and so totaly beyond the scope of your original question as to be considered spam, but there are relative levels of complexity

thanks now im gonna go shoot myself. Ive had to use that before, it was in high school AP Physics, and our teacher decided to show it to us "for a bit of fun."

 

[Cheezy the Wiz]

Oh, do you want us to explain Magnetics and Circuits, too? As they apply to electriciy? or both?
I can help with these, but to avoid worthless lengthy post i'll wait for a reply.

 

[History_Buff]

So if I chant Ohm can I conduct electricity?

I don't care what you chant, if you put a large enough potential difference (voltage) between your right and left hand, your body will conduct, and when the current crosses your heart, bad things will happen

But the flipside is also true, if swinging from a power line by one arm, you'll be perfectly fine, as all that current won't be able to create a meaningful current. But the moment you come in contact with the ground, it's bad news bears. I've also heard tale of an Australian Electric worker who managed to build a 20 kV charge on himself, without touching the ground. Rule number one of playing with circuits:

It's not the voltage that kills you, it's the current.

 

[7ronin]

May I recommend Electronics for Dummies (includes basic electricity)?