Calculate the area of cross section of a wire, if its length is 1.0m, its resistance is 23Ω and the resistivity of the material of the wire is 1.84 × 1O-6 Ωm.

We have, [where, R is a resistance]

Where, A is the area of cross-section of the wire

l = Length of the wire = 1 m

R = 23Ω

p = Resistivity of the wire = 1.84 × 10-6 Ωm

Therefore, the area of cross-section of the wire is 8 × 10-8 m2.