Question

resistance of a metal wire of length 1 m is 30 ohm and its diameter is 0.6 mm find its resistivity ?​

Answer 1

Explanation:

mark its brainleast

Given:      l = 1 m

                 d = 0.3 mm

                 A = r2 = 3.14 x 2.25 x 10-8 = 7.065 x 10-8m2

Formula:         = R x A / l

                            = 26 x 7.065 x 10-8

                            =183.69 x 10-8m

Thus, the resistivity of the metal wire at 20C is 183.69 x 10-8m.