A well insulated box has two metal plugs, each of area 10 cm² and length 10 cm, in opposite walls. Their outer ends are at 90°C and 10°C and k = 40 cal s⁻¹ m⁻¹ K⁻¹. A heater inside produces 20 cal/s (

Question

A well insulated box has two metal plugs, each of area 10 cm² and length 10 cm, in opposite walls. Their outer ends are at 90°C and 10°C and k = 40 cal s⁻¹ m⁻¹ K⁻¹. A heater inside produces 20 cal/s (1 cal = 4.2 J). Find the steady temperature of the inner surface, in °C.

TestHub · Accepted Answer

G = l k A ​ = 0.1 40 × 4.2 × 10 × 1 0 − 4 ​ = 1.68 W/K. G ( 90 − T ) + 84 = G ( T − 10 ) , so T = 50 + 2 G 84 ​ = 75.0 ∘ C.

Physics - Heat & Thermo Question with Solution | TestHub

Doubts & Discussion