How to Manipulate Ohm's Law and Joule's Law

Last Updated: March 29, 2019

The purpose of writing this article is to teach people to manipulate ohm’s law and the power dissipation rule. It’s better to know how to manipulate these formulas than trying to memorize them; it will help you better understand the formulas then different ways of writing out these rules. This will also help you better understand electricity.

Steps

1
[1]Memorize Ohm’s law (V=IR) and Joule’s law (P=IV)
2
Learn the meanings of “V”, “I”, “R” and “P” V= Voltage, I= Amperage, R= Resistance, P= Power

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3
Solving for “I” using Ohm’s law. To solve for “I” using Ohm’s law all you have to do is divide both sides of the original equation by “R” by doing this you eliminate “R” on one side of the equation and you are left with V/R=I (See Diagram 1)
4
Solving for “R” using ohm’s law. To solve for “R” using ohm’s law all you have to do is divide both sides of the original equation by “I” by doing this you eliminate “I” on one side of the equation and you are left with V/I=R (See Diagram 2)
5
Solving for “I” using Joule’s Law. To solve for “I” using Joule’s Law all you have to do is divide both sides of the original equation by “V” by doing this you eliminate “V” on one side of the equation and you are left with P/V=I (See Diagram 3)
6
Solving for “V” using Joule’s Law. To solve for “V” using Joule’s Law all you have to do is divide both sides of the original equation by “I” by doing this you eliminate “I” on one side of the equation and you are left with P/I=V (See Diagram 4)
7
Inserting ohm’s law into Joule’s Law. To insert V=IR into P=IV you replace the V in the power dissipation rule with IR and get P=IIR which simplifies to P=I^2R
8
You can also manipulate Step 8 (P=I^2R) using the same method as step 3 and get R=P/I^2 and I^2=P/R
9
Inserting step 3 of Ohm’s law into Joule’s Law. To insert I=V/R into p=IV you replace “I” in power dissipation rule with V/R and get P= (V/R) V which simplifies to P=V^2/R
10
You can also manipulate step 9 (P=V2/R) by multiplying both sides of the equation by “R” you eliminate the “R” on one side and get PR=V^2 (see diagram 5) and by using the same method as step 3 you can get R=V^2/P

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