The Cylindrical Filament in a Light Bulb Has a Diameter

question 49

Multiple Choice

The cylindrical filament in a light bulb has a diameter of 0.050 mm,an emissivity of 1.0,and a temperature of 3000°C.How long should the filament be in order to radiate 60 W of power? (σ = 5.67 × 10^-8 W/m² ∙ K⁴)

• A)11 cm
• B)9.4 cm
• C)8.6 cm
• D)7.2 cm
• E)5.9 cm

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