A 150 W heating coil (like a light bulb) is designed to operate from 125 V. The coil is made from a filament with a temperature coefficient of a = 2.3x10-3 /°C. When thefilament is connected to 125 V, it is hot and glowing and its temperature is 5 times room temperature. What is the resistance of the filament (in ohms) at roomtemperature? Take room temperature to be 20 °C.

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Answered: A 150 W heating coil (like a light…

University Physics Volume 2

18th Edition

ISBN:9781938168161

Author:OpenStax

Publisher:OpenStax

Chapter9: Current And Resistance

Section: Chapter Questions

Problem 70AP: A 10.00-meter long wire cable that is made of copper has a resistance of 0.051 ohms, (a) What is the...

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A small bulb delivers an electrical power of 7.5 W when operated at 125 V. The tungsten filament has a temperature coefficient of resistivity of alpha = 4.5 x 10 ^ (- 3 / ° C) When the filament is hot bright, its temperature is seven times the ambient temperature of a room (20 ° C). What is the resistance of the filament (in ohms) at room temperature? a.5630 b.4530 c.1911 d.1280 e.1350
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