Задача 50295.

Neglecting losses in the thermal conductivity, find the power of electric current needed for the filament 1 mm in diameter and 20 cm in length up to 2500 K. The temperature Assume that thread radiates as a black body and the establishment of thermal equilibrium in all liberated filaments heat is lost by radiation.

Detailed solution with a short recording conditions, laws and formulas used in the decision, the withdrawal of the calculation formula and the answer.
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