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

The rate at which heat is developed in the electric heater will be given by the power of the heater.
Now, Power, `P = I^(2) xx R`
`P= (15)^(2) xx 8`
`P= 225 xx 8`
`P = 1800 W` or `1800 J//s`
Thus, the rate at which heat is developed in the heater is 1800 joules per second.