# A 100W water heater coonected across 230V heats a certain quantity of waterby 5degree celsius in 10s.If two such heaters are connected in series and immersed in the same quantity of water by what temperature would the water rise in 20s?

1
by TvesaSanghvi

2015-10-25T20:18:05+05:30

### This Is a Certified Answer

Certified answers contain reliable, trustworthy information vouched for by a hand-picked team of experts. Brainly has millions of high quality answers, all of them carefully moderated by our most trusted community members, but certified answers are the finest of the finest.
100 W = Power  = V² / R
Voltage V = 230 V

When two heaters are connected in series, the voltage across each of them becomes V/2.  Its resistance remains same.

So the power dissipated by each heater becomes 1/4 of 100 W ie.,  25 W.
So the total heat power of two heaters = 50 W

heat supplied = power * time = mass of water * specific heat * ΔT
=>   ΔT  is proportional to power * time duration

T °C / 5° C =  ( 50 W * 20 sec ) / (100 W * 10 sec)

T = 5 °C
click on thanks button above ;;;select best answer