Question

1/ Resistance of a metal wire of length 2 m is 50ohm
at 20°C. If the diameter of the wire is 0.4 mm, what
will be the resistivity of the metal at that
temperature?​

Answer 1

Answer:

Resistivity = 0.0314 Ω m

Explanation:

Given that,

Length = L = 2m

Resistance = R = 50Ω

Radius = Diameter/2 = 0.4/2 = 0.2 mm = 0.2×10⁻³ m = 2×10⁻⁴ m

Area = A = πr² = 3.14 × 4 × 10⁻⁸ = 12.56×10⁻⁸ m²

Resistivity = ρ = ?

We know that,

R = ρL/A

ρ = RA/L

ρ = 50×12.56×10⁻⁸/2×10⁻⁴

ρ = 314×10⁻⁴ = 0.0314 Ω m

Answer 2

Answer:

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