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Derive an expression for electric energy...

Derive an expression for electric energy consumed in a device in terms of V, l and t, where V is the potential difference applied to it, l is the current drawn by it and tis the time for which the current flows?

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We know that work done = W = QV
`:. P = (W)/(t) `
Now `P = (QV)/(t)`
V=IR
`:. P =(Q)/(t) IR =I^(2) R`
Energy `=P xxt`
`= I^(2) R xxt`
`=(V)/(R^(2)) Rt`
`=(V^(2))/(R) t `
Energy `=(V^(2))/(R) t`
Where V = voltage R = resistance , t = time .
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