question_answer 17)

An electric heater of resistance 8 draws 15 A from the service mains for 2 hour. Calculate the rate at which heat is developed in the heater.

Answer:

Here, I = 15A, R = 8 , t = 2h Rate at which heat is developed, i.e, electric power, P = I2 R = (15)2 × 8 = 1800 W = 1800 J/s