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The operating temperature of an in cande...

The operating temperature of an in candescent bulb (with tungsten filament) of power 60 W is 3000 K. If the surface area of the filament be 25 `mm^2`, find its emissivity e.

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To find the emissivity \( e \) of the tungsten filament in the incandescent bulb, we can use Stefan-Boltzmann's law, which states that the power emitted by a black body is proportional to the fourth power of its temperature. The formula can be expressed as: \[ P = e \cdot A \cdot \sigma \cdot T^4 \] Where: - \( P \) is the power (in watts), ...
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