I have been facing a problem related to electricity since quite a long time. The topic is heating effect of electric current.

My textbook says that the electrical energy is used up in useful work such as rotating the blades of a fan, etc in an electrical circuit. But when we consider a purely resistive circuit, consisting of a battery and a resistor, the entire electrical energy gets dissipated as heat through the resistor.

Then there is the derivation of the formula, that when a charge Q flows across a resistor across which the voltage is V, then the work done by the cell to move the charge will be VQ.

Let I be the current in the circuit and t be the time through which the charge Q flows across the resistor.

Then the power of the cell will be P = W / t

P = VQ / t ....... P = VI

The energy supplied by the cell will be E = P x t

And this energy is dissipated as heat it is written....

Therefore, H = VIt

Q 1) what is meant the electrical energy? The kinetic energy of the electrons??

Q2) How EXACTLY does this electrical energy get converted into heat energy in a resistor? why does this change even occur?

What happens to the charges inside the resistor, for why does the cell has to expend its energy to keep the charges flowing through the resistor ? Related question,

Why does this heating not occur in a conducting wire?

Please explain the phenomenon according to the math used....

Thank you so much