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## Main Question or Discussion Point

Hi everyone,

I'm struggling to understand what I think is a very basic concept: Joule's law of heating. Allow me to explain my confusion:

We know that voltage can be expressed as:

And power can be expressed as:

Making power equivalent to:

According to my textbook, Joule's law of heating can be written as:

Where

If you are reading this and think you might be able to help, I would be very grateful!

I'm struggling to understand what I think is a very basic concept: Joule's law of heating. Allow me to explain my confusion:

We know that voltage can be expressed as:

**V = I · R**

And power can be expressed as:

**P = I · V**

Making power equivalent to:

**P = I**

^{2}· RAccording to my textbook, Joule's law of heating can be written as:

**E = I**

^{2}· R · tWhere

**E**is the amount of electrical energy that gets converted to thermal energy. What confuses me is that – since this equation is equal to**P · t**– it is equal to simply measuring the total amount of electrical energy. To me, this says that it is always the total amount of electrical energy that gets converted to thermal energy, and that doesn't really make sense to me. I would think that*part*of the electrical energy dissipates as heat; not all of it!If you are reading this and think you might be able to help, I would be very grateful!