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Question
How is the amount of heat produced calculated due to the passage of current in a metallic conductor? Derive an expression for it.
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Solution
It is calculated by finding the amount of work done in sending the current through the conductor.
Let a current of i ampere flow in conductor having a potential difference of V volt across its ends for t second.
If Q be the amount of charge that flows in the conductor in t second.
Then Q = i × t coulomb
Since the amount of work done in: moving a charge Q across the ends of a conductor is W.
then W = Q × V joule
i.e., = i × t × V = Vit joule
or, the amount of heat produced Q = V it joule.
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