Question

(C) The resistance of a metal wire of length 1 m is 26 22 at 20°C. If the diameter of the wire is 0.3 mm, what
will be the resistivity of the metal at that temperature ?​

Answer 1

Answer:

1.84 × 10^-6 ohm metre.

Explanation:

R = 26 ohm

length(L) = 1m

d = 0.3mm

r = d/2 = (0.3 × 10^-3)/2

= 0.15 × 10^-3m

A = pi r^2

= 3.14 × (0.15 × 10^-3)^2

= 0.071 × 10^-6 metre square

R = [resistivity(p) × L]/A

(or) resistivity = (R×A)/L

= (26 × 0.071 × 10^-6)/1

= 1.84 × 10^-6 ohm metre...