Derive an expression for heat produced in a conductor using Joule's la

1.	Derive an expression for heat produced in a conductor using Joule's law of heating.
Answer» <P> Solution :Let 'V' be the potential difference applied across the two terminals of a resistor of resistance 'R' by a cell and 'I' be the current flowing through the resistor in time 't'. ii. If charge Q flows through the resistor, then the electrical power 'P' is given by `P=("Energy")/("time")"...(1)"` where, energy is the work done by cell to move charge Q across the resistor `therefore"Energy " = VxxQ"...(2)"` `therefore"P"=(VQ)/(t)"....[from equations (1) and (2)]"` `=VI"..."(because(Q)/(t)=I)"....(3)"` iii. The cell PROVIDES the energy to the resistor which is CONVERTED into heat energy, given by `H=Pxxt=VxxIxxt"...[from (3)](4)"` iv. According to Ohm's LAW, `V=IR"...(5)"` From EQUATION (4) and (5), `H=(V^(2)t)/(R) or H=I^(2)Rt` This is called as Joule's law of heating.

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