tolong ya dijawab, dikumpulin besok

R = 30 Ω
l = 1 m
A = 0,4 mm² = 4 x 10⁻⁷ m²

ρ = _ ?
R = ρ l / A
ρ = R A / l
= 30 • 4 x 10⁻⁷ / 1
= 1,2 x 10⁻⁵ Ω m