In a circuit consisting of three identical conductors connected in parallel and connected to the network

In a circuit consisting of three identical conductors connected in parallel and connected to the network, a certain amount of heat was released in 40 seconds. Specify the time for which the same amount of heat is if the conductors are connected in series.

If an electrical circuit, consisting of three identical conductors with resistance R₀, connected in parallel, is connected to the network with voltage U, then the current during t₁ = 40 s will release a certain amount of heat in the circuit: Q = (t₁ ∙ U ^ 2) / R₁, where the total the resistance of the circuit is found by the formula: 1 / R₁ = 1 / R₀ + 1 / R₀ + 1 / R₀ or R₁ = R₀ / 3. Then Q = 3 ∙ t₁ ∙ U ^ 2 / R₀. To determine the time t₂, during which the same amount of heat will be released, if the conductors are connected in series, we first find the total resistance of the circuit for this case: R₂ = R₀ + R₀ + R₀ or R₂ = 3 ∙ R₀. Then:
t₂ = Q ∙ R₂ / U ^ 2;
t₂ = (3 ∙ t₁ ∙ U ^ 2 / R₀) ∙ 3 ∙ R₀ / U ^ 2;
t₂ = 9 ∙ t₁;
t₂ = 9 ∙ 40 s;
t₂ = 360 s.
Answer: in 360 s, the same amount of heat will be released in the circuit if the conductors are connected in series.