The Tungsten Filament of a Light Bulb Has an Operating

question 67

Multiple Choice

The tungsten filament of a light bulb has an operating temperature of about 2,060 K.If the emitting area of the filament is 0.8 cm²,and its emissivity is 0.68,what is the power output of the light bulb? (σ = 5.67 × 10−⁸ W/m²⋅K⁴)
​

• A) 82 W
• B) 56 W
• C) 555 W
• D) 51 W
• E) ​48 W

---

Definitions:

Net Operating Income

The income generated from normal business operations, calculated by deducting operating expenses from gross income.

Absorption Costing

An accounting method that includes all manufacturing costs (direct materials, direct labor, and both variable and fixed overhead) in the cost of a product.

Fixed Costs

Costs that remain constant in total regardless of changes in the level of the business activity or production volume.

Product Costs

Costs that are directly associated with the production of goods or services, including direct materials, direct labor, and manufacturing overhead.