Question

Calculate the resistivity of the material of a wire of length 1m, radius 0.01 cm and of resistance 20 ohms.

Answer 1

given length is 1m radius is 0.01cm resistance is 20 ohms
$area \: is \: \pi {r}^{2}$
22×1×1/10^4×10^4×7
3.14 × 10^-8m^2
resistivity=resistance × area/length
20×3.14×10^-8/1
answer may be is 628×10^-8
$628 \times {10}^{ - 8?}$