1. The problem statement, all variables and given/known data We are given two identical thermophores. It is known that one of them can boil a liter of water in t = 600 s. How much time would it take to boil one liter of water if we used two of these thermophores, connected a) in a series circuit b) in a parallel circuit Voltage: 230 V t = 600 s U = 230 V I1 = I2 2. Relevant equations W - energy required to boil water W = UIt 3. The attempt at a solution a) series circuit Since the thermophores are in a series, each of them will share the same current, thus: W = (UI+UI)t = 2UIt => t = 300 s b) parallel circuit The thermophores are in a parallel connection, which means that they will share the current, and so each of them will be empowered with the current 0.5I W = 0.5I U t + 0.5 I u T = UIt => t = 600 s However, I doubt that this solution is valid. Could you, please, give me some tips or reference how to tackle this problem? Thank you very much in advance.