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1. |
A 100 W light bulb has a tungsten filament (emissivity = 0.30) which is required to operate at 2780 K. If the bulb is completely evacuated, calculate the minimum surface area of the tungsten filament |
A. | 0.98 * 10¯⁴ m² |
B. | 1.98 * 10¯⁴ m² |
C. | 2.98 * 10¯⁴ m² |
D. | 3.98 * 10¯⁴ m² |
Answer» B. 1.98 * 10¯⁴ m² | |