Ohm's Law

So, I'm sitting here in my Cisco Class, struggling to understand these questions, and what not.

This is, by far, the most trouble I have ever had, relating to computers.

Here is one of the questions.

5. The yellow wire connected to a power supply carries 12V. If the power supply provides 60W of power to the yellow wire, how much current is passing through the yellow wire?

I came up with 5 Amperes aka 5 Amps. But I'm not entirely sure.

Anyone got some nifty tricks to help me learn this?

johnsmith45jock said:

I feel like I'm helping you cheat on a test. Divide 60 by 12 = 5.

Nope. I was given similar materials as to what was posted above, except it confused the hell out of me.

So it's I = P / V which translates to Current equals (=) Power / Voltage / I = 60W / 12V. I = 5 Amps


I came up with the answer, but again I was confused. This should tell you why.

derekimo said:

Your answer is right, what part confuses you?

Here's a calculator to check your math.

Ohm's Law Calculator

60W/12V = 5A

Well.. Having so many options opposed to having just 3. Like this question I have here.

3. Re-arrange the Ohm's Law equation to solve the following:

R =

And thats it. But now that I've looked at it; its literally the same equation for what you previously answered, only backwards. R = W / V. Least I think its that.

Well... If Ohm's Law is V = I*R then, wouldn't R = V / I be it then? Because V = I*R is the original equation.


As you can see, my mathematical intelligence is fairly low when it comes to things of this caliber. But I still try :)

Ohm's law would be easier if it used
W=watts
V=volts
A=amps
O=resistance
The "I" and "P" and always confuse me.