berapa luas penampang kawat bila mempunyai pnjang 500cm dgn hambatan sbsar 1000 ohm dan hambatan jenis besi sebesar 1×10-7 ohmmeter

500 cm = 5 m
R = ρ l/A
1000 = 1x10⁻⁷ . 5/A
1000A = 5x10⁻⁷
A = 5 x10⁻⁷/1000
A = 5 x 10⁻⁷/10³
A = 5 x 10⁻¹⁰ mm²

dik.
l = 500 cm = 5 m
R = 1000 ohm = 10^3 ohm
rho = 1 x 10^-7 ohm meter
dit. A=
R = rho.l/A
A = rho.l/R
= 1 x 10^-7.5/10^3
= 5 x 10^-7 x 10^-3
= 5 x 10^10 m^2