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.

Explanation

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.