Question

calculate the resistance of copper wire 20 metre long and diameter is diameter

Answer 1

20 meter long and diameter of 0.05 cm ( specific resistance of copper =1.678×10^-6 ohm- cm.

Answer 2

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)     aise hi solve hoga