Question

Calculate the resistance of a 1 km long copper wire of area of cross section 2x10^-3 .The resistivity of copper is 1.623x10-8Ωm.​

Answer 1

Answer:

We know that resistance R=Aρ×l, here, l=1km=1000m,A=0.02cm2,ρ=1.62×10−8Ω−m

                                                =2×10−2×10−41.62×10−8×1000

                                            =8.1Ω

so resistance will be 8.1Ω