50. A mall bulb is rated at 7.50 W when operated at 125 V. The
tungsten filament has a temperature coefficient of resistivity a = 4.50 x 10-3/ ℃. Wher is hot and glowing, its temperature is seven times room temperature (20 ℃). What is the resistance of the filament (in ohms) at room temperature?
(A) 240
(B)1350
(C) 2080
(D) 4530
(E) 5630
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