Question

Question 17
An electric heater of resistance $8\Omega$ draws 15 A from the service mains 2 hours. Calculate the rate at which heat is developed in the heater.

Answer 1

Rate of heat produced by a device is given by the expression for power as, $P=I^{2}R$
Where, resistance of the electric heater, $R=8\Omega$
Current drawn, I = 15 A
$P=(15{)}^2\times 8=1800J/s$
Therefore, heat is produced by the heater at the rate of 1800 J/s.