Question

Calculate the quantity of heat produced in a $20\Omega$ resistor carrying 2.5A current in 5 minutes.

Answer 1

Given: $I=2.5A,R=20\Omega ,t=5\times 60=300s$.
Heat Produced $=\left(PotentialDifference\right)\times \left(Current\right)\times \left(time\right)$
$=VIt$
$=I^{2}Rt$ (ohm's law, $V=IR$)
$=\frac{25}{10}\times \frac{25}{10}\times 20\times 300=37500J$
$=37.5kJ$
Hence, $37.5kJ$ heat is produced.