Write down an expression for the resistance of a metallic wire in terms of the resistivity. b) What will be the resistance of a metal wire of length 2 metres and area of cross-section 1.55×10-6m2, if the resistivity of the metal be 2.8×10-8Ωm?

1. Following is the expression for the resistance of a metallic wire in terms of the resistivity: R = ρl/A

Where,

R is the resistance of the wire ρ is the resistivity of the wire

A is the cross-sectional area of the wire l is the length of the wire

1. Given, l = 2m

A = 1.55×10-6m2 ρ = 2.8×10-8Ωm

We know that, R = ρl/A

= 0.036 ohm