Question

A wire of resistance 12.2 ohms and length 80cm has area of cross section 0.020cm^2. Calculate resistivity of the wire?

Answer 1

Resistance (R) = 12.2 ohm

Cross section area (A) = 0.020 cm2= 0.020 × 10-4 m2

Length (l) = 80 cm = 0.8 m

R=ρlA12.2=ρ0.80.020×10−4∴ρ=0.020×10−4×12.20.8ρ=0.305×10−4ρ=30.5×10−6Ωm