Question

calculate the resistance of 199m Cooper wire. the diameter pf wire is 1 mm take p(cm)=1.7×10^-8 root metre

Answer 1

Answer:

Explanation:

: Length of the copper wire l = 200 m

       Diameter of the copper wire = d = 1 mm = 1 x 10−3 m

       Radius of the copper wire r = d/2 = 5 x  10−4 m

       Area of cross section of the copper wire A = π r2 = 3.14 x (5 x  10−4 m)2

                                                                                                      = 78.5 x 10−8 m2

      Resistivity of copper ρ = 1.7 x 10-8 Ωm

      Resistance of the copper wire R = ρl/A = 1.7 x 10-8 Ωm x 200 m/(78.5 x 10−8 m2)

                                                                                   = 4.33 Ω