Question

Resistance of a metal wire of length 2m is 30ohm at temperature 25°C, If diameter of the wire is 0.6mm then what will be the resistivity of the metal at that temperature?​

Answer 1

Answer:

Explanation:

=> Resistance, R = 30 Ω

=> Length, L = 2 m

=> Diameter, d = 0.6 mm = 0.6 * 10⁻³ m

=> Area = πr² = πd² / 4 (d = 2r)

= 3.14 * (0.6 * 10⁻³)² / 4 m²

= 28.26 * 10⁻⁸ m²

=> The resistivity of the metal at that temperature :

R = PL / A

P = RA / L

= 30 * 28.26 * 10⁻⁸ / 2

= 423.9 * 10⁻8

= 4.239 * 10⁻⁶ Ωm at 25°C

Thus, the resistivity of the metal at that temperature 4.239 * 10⁻⁶ Ωm