guy's firstly I like to say this site needs to be more adversite i simplly couldn't find it in when i type in circutirs fourms not a lot came up from google.


my problem is that i just can't get the maths around my head with the Ohm's law is there anyone who can explain to me how to work out R if the value was example 10K and the volt was 5V then what is the I and how do you work this out can i have step by step example please.

 

Well you know this
R = 10k
V = 5V
I = ?

and I'm pretty sure your circuit looks like this

+5V
|
|
|
\
/ 10K ohms of resistance
\
/
|
|
|
Ground

You know 5 volts is droped across the entire 10k ohm resistor (10,000 ohms)
Therefore you use ohms law V=I*R where V = voltage in volts, I = current in amps, R = resistance in ohms.

So you can take 5V = I * 10,000ohms
5volts/10,000ohms = I in amps = 0.0005 Amps or 0.5milliamps

Best of luck,

Matt

 

The current on a wire flowing from points A to B (Iab) is given by:

Iab = Vab/R

where Vab = Va - Vb, Va is the voltage at point A, Vb is the voltage at point B.

 

A good way to remember Ohm's Law is the triangle method:

Voltage
---------
Current | Resistance

I.e:
Voltage = Current x Resistance
Current = Voltage / Resistance
Resistance = Voltage / Current