Elec Class
learn electricity hands-on
Solved exercise · level 4 of 5
Skills: Build, Calculate
Source G has E = 12 V and r = 1 Ω. Set R1 so that the generator's electrical efficiency is η = 0.9 (within 3 %), i.e. U = η · E.
Parametric exercise: the values change with every draw; these are one example.
η = R / (R + r) → R = r · η / (1 − η) = 9 Ω; then U = η · E = 10.8 V. The larger R is compared with r, the better the efficiency.