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.

Explanation

`R= 8 Omega I = 15 A t, = 2h =2 xx60 xx60 s `
`H= I^(2) Rt = (15)^(2) xx8xx2xx60xx60`
Rate at which heat produced :` = (H)/(t)`
`= (15^(2)xx8xx2xx60xx60)/(2xx60xx60)` = 1800 W