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प्रश्न
A 6 m long wire has diameter 0.5 mm. Its resistance is 50 Ω. Find the resistivity and conductivity.
उत्तर
Given: l = 6 m, D = 0.5 mm, r = 0.25 mm = 0.25 × 10−3 m, R = 50 Ω
To find: i. Resistivity (ρ)
ii. Conductivity (σ)
∴ ρ = `"RA"/"l"`
`ρ = ("R"pi"r"^2)/"l"`
ρ = `(50xx3.142xx(0.25xx10^-3)^2)/6`
ρ = = 1.636 × 10−6 Ω m
∴ σ = `1/"ρ"`
∴ σ = `1/(1.636xx10^-6)`
= 0.612 × 10−1 × 106 ....(Using reciprocal from log table)
= 6.12 × 105 Ω/m
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