A 1.5 m wire of resistance 5 Ω and diameter 1.0 mm is coated with plastic 0.1 mm thick. A current of 3 A flows. The conductivity of the plastic is 0.5 W m⁻¹ K⁻¹. Find the temperature difference across

Question

A 1.5 m wire of resistance 5 Ω and diameter 1.0 mm is coated with plastic 0.1 mm thick. A current of 3 A flows. The conductivity of the plastic is 0.5 W m⁻¹ K⁻¹. Find the temperature difference across the insulation in steady state, in °C.

TestHub · Accepted Answer

P = I 2 R = 45 W. Radii 0.5 mm and 0.6 mm. Δ T = 2 πk L P ln ( r 2 ​ / r 1 ​ ) ​ = 2 π × 0.5 × 1.5 45 × 0.1823 ​ = 1.74 ∘ C.

Physics - Heat & Thermo Question with Solution | TestHub

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