An electric current through a tungsten filament maintains its temperature at 2800 K.Assume the tungsten filament behaves as an ideal radiator at that temperature.If the radiating area of the filament is 2.0 × 10^-6 m²,at what rate does it radiate energy? (σ = 5.670 × 10^-8 W/m² ∙ K⁴,Wien displacement law constant is 2.90 × 10^-3 m ∙ K) A)5.5 W B)7.0 W C)8.5 W D)10 W E)11.5 W

Question

Quizplus · Accepted Answer

The rate at which the filament radiates energy can be calculated using the Stefan-Boltzmann law:
P = σAT^4
where P is the power radiated, σ is the Stefan-Boltzmann constant, A is the radiating area, and T is the temperature in Kelvin. Plugging in the given values, we get:
P = (5.670 × 10^-8 W/m^2∙K^4)(2.0 × 10^-6 m^2)(2800 K)^4
P = 7.03 W
Rounding to the nearest tenth, we get:
P = 7.0 W
Therefore, the best choice is B.

An Electric Current Through a Tungsten Filament Maintains Its Temperature