Ohm's Law (1 Viewer)

[davidbarnes]

I am trying to understand Ohm's Law. Can anyone explain the basics of this to me?

I placed this in this forum as this is the education forums...

 

[airie]

Put it simply, I=V/R, R=V/I or V=IR, whatever form you wanna put it. It states that when one of I and R is constant, the other is in direct proportions to V, and when V is constant, I and R are in inverse proportions.

That's the very basics of Ohm's Law, you'll learn it in the Electricity topic next year. I'm not sure what exactly you wanted to be explained...

 

[alcalder]

Ohm's Law tells us about the current conductivity of a substance or RESISTIVITY (p).

The resistivity of a substance is given by the amount of electric field that is needed to make a certain current per area flow through a conductor. Each material has a specific resistivity that you can look up. NOW this we can use to talk about the resistance (R) of a substance.

R = pl/A

Where p = resistivity (a constant for a particular material) [in Ohm metres, Ωm]
l = length of the material [in metres, m]
A = cross-sectional area of material [in metres sqaured, m²]

Thus we can also state Ohm's Law as

R= V/I

R = resistance [in Ohms, Ω]
V = electric potential difference between the ends of the conductor [in Volts, V]
I = current through the conductor [in amps, A]

This form of Ohm's law refers only to the actual piece of material, not to the general metal or whatever. It is the one most used and is fundamental in all electrical calculations.

Some conductors are Ohmic conductors and if you drew a V versus I graph it would be a straight line and the gradient would equal resistance. However, there are many non-ohmic conductors eg light globes (because temperature affects resistivity, p), semi-conductors and super-conductors.

That was not a simple explanation for Ohm's Law but I hope it made sense. Ohm's Law is THE most important equation you can know in electrical interactions.

 

[jyu]

I am trying to understand Ohm's Law. Can anyone explain the basics of this to me?

I placed this in this forum as this is the education forums...

:wave:

 

[Bank$]

If u want to understand why ohms law happens to work u are better of using anologys like this one: W= F*S

F is force and S is displacement and W= work

Voltage is the pushing power the more u push the more u work so u can say V =W

now Force is like resistance because the more resistance the more force u need so it can be said R=F

now current is how many coulombs per second so more current means more coulombs per second and when u line these charges up its a line where more charges the longer the line is so I=S

now i just made this anology up on the spot so most likely there will be better ones u just have to imagine anyway i hope this helps

 

[twilight1412]

ohms law ....

potential difference (V) is proportional to the current (A) in a series circuit

so basically V=KA where K is a constant which varies depending on the circuit

ohms law takes this and says that K = R(resistance of the circuit)

so basically you end up with

V=RI