Labo Élec
electrical lab simulator
Exercise from the chapter "Ohm's law & resistance"
Level 3 of 5 · Skills: Analyse
Two wires of the same metal (aluminium). F2: length 20 m, diameter 0.8 mm, resistance 1.11 Ω. F1: length 40 m, diameter 1.6 mm.
Without computing ρ, predict the resistance of F1.
Parametric exercise: the values change with every draw; these are one example.
R = ρ·l/S: length × 2 and diameter × 2 (cross-section × 2²) → R = 1.11 × 2 / 2² = 557 mΩ.