Question

find the area of cross section of the wires having resistance =0.005 m​

Answer 1

Answer:

85.7 Ohms

Explanation:

First make uniform measurements units

Copper resistivity is 1,68 x 10 ^ -8 Ohm Meter

Length 1 Km = 1000 m

Diameter = 0.5 mm = 0.005 meter

Area = Pi x D x D /4 = Pi x 0.0005 x 0.0005 /4 = 1.96 x 10^-7 Sq Mtr

Resistance = (Resistivity x Length)/Area

= 1,68 x 10^-8 x 1000 /(1,96 x10^–7 = 857 x 10^-1 = 85.7 Ohms