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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Definitions:

Voltage Drop

The decrease in voltage along a conductor or component while it conducts electric current.

Applied Voltage

The electrical potential difference purposely introduced across a device or component, driving the current through it.

Resistance

An electrical quantity that measures how the device or material reduces the electric current flow through it, measured in Ohms (Ω).

Voltage Across

The electrical potential difference between two points in a circuit, driving the flow of current between those points.