Question

the resistivity of a given wire of cross session area 0.7mm² is 49×10⁴.calcuate the resistance of a 2m lenght of wire​

Answer 1

R = 1.4GΩ.

The relation between the resistance and the resistivity is given by the equation R = ρL/A, where ρ is the resistivity of a given material, L is the length and A is the cross-sectional area of the material.

To calculate the resistance of a wire of L = 2m, ρ = 49x10⁴Ω.m and A = 0.7mm² = 0.7x10⁻³m² we have to use the equation  R = ρL/A.

R = [(49x10⁴Ω.m)(2m)/0.7x10⁻³m²

R = 98x10⁴Ω.m²/0.7x10⁻³m²

R = 1.4x10⁹Ω = 1.4GΩ