Question

A wire of length 2 m diameter 1 mm has 50 m ohm resistance.calculate the resistivity of the material of the wire ?

Answer 1

Answer:

312.5pi×10^-6(or) 981.25×10^-6

Answer 2

Answer:

The resistivity of the wire is 2*10⁻⁸Ωm.

Explanation:

Given:

Resistance(R)=50*10⁻³Ω

Length(l)=2m

Diamater=1*10⁻³m

∴Radius=0.5*10⁻³m

To find: Resistivity of the material=?

Solution:

We know that,

Resisitvity=$\frac{RA}{l}$

Area=$\pi r^{2}$

=3.14*(0.5*10⁻³)²=7.85*10⁻⁷m²

∴Resistivity=7.85*10⁻⁷ *50*10⁻³/2=2*10⁻⁸Ωm

Therefore, the resistivity of the wire is 2*10⁻⁸Ωm.