Question

Two identical heaters 240v, 1000W are connected in series across a 240v supply the combined power is?

options:-
1. 2000W
2. 1000W
3. 500W
4. 4000W

please answer with full explanation

Answer 1

Let resistance of each heater be `ROmega`

Given that the power of each heater is 1000W when connecred across 240V.

So `1000=240^2/R`

`=>R=240^2/1000Omega`

When two heaters are connected in serises total resistance `2R=240^2/500 Omega`

Then total power consumed `=240^2/(240^2/500)=500W`