Question

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

Answer 1

Here, `I = 15 A, R = 8 Omega, t = 2 h`
Rate at which heat is developed, i.e., electric power, `P = I^2 R = [(15)^2 xx 8] W = 1800 W = 1800 J//s`.