Question

A wire is 1m long 0.2 mm in diameter and has resistance of 10Ï calculate its resistivity

Answer 1

Hey mate ^_^

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Solution:
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Length l = 1.0 m

Diameter d = 0.2 mm

Radius r = 0.1 mm = 1.0×10^(-4) m

Resistance R = 10 Ω

Let resistivity be ρ

Now,

R = ρ l/A

So,

ρ = (R×A)/l
= R×π×r² /l
= 10×(22/7)×[1.0×10^(-4)]² / 1.0
= 22×10^(-7) / 7

So,
ρ = 3.14 × 10^(-7) Ωm

#Be Brainly❤️

Answer 2

l=1m ,d=0.2mm=>r=0.1mm and R=10 ohm

by using the formula,

R= p౹/ A

= p౹/ πr²

therefore, p= Rπr²/l

= 10× 3.14×( 0.1× 10 -³)²

= 10× 3.14× 0.1×0.1× 10 to the power -6

= 0.314× 10 to the power-6

= 3.14× 10 to the power-7 ohm- m

hence, the resistivity of the conductor is 3.14× 10 to the power-7 ohm- m

HOPE HELPS ✌️