Labo Élec
electrical lab simulator
Exercise from the chapter "Induction & self-induction"
Level 4 of 5 · Skills: Calculate
A copper bar of resistance 40 µΩ rests on two parallel rails 20 cm apart. When a voltage of 1.6 mV is applied between the rails, the dynamometer holding the bar reads 4 N. What is the flux density normal to the plane of the rails?
Parametric exercise: the values change with every draw; these are one example.
I = U / R = 1.6·10⁻³ / (40·10⁻⁶) = 40 A; B = F / (I · l) = 4 / (40 × 20·10⁻²) = 0.5 T.