Question

An electric iron of resistamce 20 ohm takes a current of 5a .Calculate the heat developes in 30 sec

Answer 1

Given
Resistance r=20ohm
Current i=5Amp
Time t=30sec
$wkt \\ q = {i}^{2} rt \\ q = {5}^{2} \times 20 \times 30 \\ q = 15000joules \\ q = 15kj$
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