Labo Élec
electrical lab simulator
Exercise from the chapter "Real generators & loads"
Level 3 of 5 · Skills: Calculate
A circuit contains two accumulator cells (e = 1.2 V, r = 0.02 Ω and e′ = 2 V, r′ = 0.01 Ω) connected in opposition through a resistance R = 0.02 Ω. What is the current when the circuit is closed?
e = 1.2 V · r = 0.02 Ω · e′ = 2 V · r′ = 0.01 Ω · R = 0.02 Ω
Parametric exercise: the values change with every draw; these are one example.
Guided problem in 4 steps: unknown, formula, units, data, result.
The stronger one (e′) sets the direction: ΣE − ΣE′ = ΣR · I → I = (e′ − e) / (r + r′ + R) = (2 − 1.2) / (0.02 + 0.01 + 0.02) = 16 A. Cell e is being recharged.