Question

alculate the resistance of 50 cm length of wire of cross sectional area 0.01 mm2

and the resistivity of

5×10-8 Ωm.​

Answer 1

Resistance, R = ρL/A

Where:

 ρ: Resistivity constant of the material, in Ω.m

 L: Length of the wire, in meter

 A: Cross sectional area of the wire, in m^2

 R: Resistance, in ohms (Ω)

Given,

ρ = 5×10^-8 Ωm.​

L = 50 × 10^-3 m

  = 5 × 10^-2 m

A = 0.01mm^2

  = 10^-8m^2

now, substitute values

R = (5 × 10^-8 × 5 × 10^-2)/(10^-8)

R = (5 × 10^-8 × 5 × 10^-2 × 10^8)         [1/10^-8 = 10^8]

R = 25 × 10^-2

R = 0.25Ω

Hope this helps