Question

find the resistance of a nichrome wire of length 80,m and of cross section 2mm if resistivity of nichrome is 10^-4 ohms

Answer 1

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We know that,

Resistance = Resistivity × Length/Area

Given that,

Resistivity = ρ = 10⁻⁴

Length = L = 80m

Area = A = πr² = 3.14×(2×10⁻³)²

        = 3.14×4×10⁻⁶

       = 12.56×10⁻⁶ m²

Hence,

R = ρL/A

R = 10⁻⁴×80/12.56×10⁻⁶

R = 6.369×10⁶⁻⁴

R = 6.369×10² = 636.9 Ω

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