Labo Élec
electrical lab simulator
Exercise from the chapter "Ohm's law & resistance"
Level 3 of 5 · Skills: Calculate
At what temperature is the field winding of a running generator, given that its resistance is 120 Ω at 25 °C and 153 Ω in operation? (α = 0.004 /°C)
Rθ₁ = 120 Ω · θ₁ = 25 °C · Rθ₂ = 152.7 Ω · α = 0.004 /°C
Parametric exercise: the values change with every draw; these are one example.
Guided problem in 4 steps: unknown, formula, units, data, result.
R₀ = 120 / (1 + 0.004 × 25); θ₂ = (Rθ₂ / R₀ − 1) / α = 100 °C.