A 100 W tungsten light bulb has a resistance | vedclass

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(B) Let $t_2$ be the temperature of the filament when the bulb is turned $ON$ and $t_1$ be the ambient temperature when the bulb is turned $OFF$.Given

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$2025$

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(B) Let $t_2$ be the temperature of the filament when the bulb is turned $ON$ and $t_1$ be the ambient temperature when the bulb is turned $OFF$.Given:$R_{t_2} = 250 \ \Omega$$R_{t_1} = 25 \ \Omega$$t_1 = 25^{\circ} C$$\alpha = 4.5 	imes 10^{-3} /^{\circ} C$Using the formula for temperature dependence of resistance:$R_{t_2} = R_{t_1} [1 + \alpha(t_2 - t_1)]$$250 = 25 [1 + 4.5 	imes 10^{-3} (t_2 - 25)]$Divide both sides by $25$:$10 = 1 + 4.5 	imes 10^{-3} (t_2 - 25)$$9 = 4.5 	imes 10^{-3} (t_2 - 25)$$t_2 - 25 = \frac{9}{4.5 	imes 10^{-3}}$$t_2 - 25 = 2 	imes 10^3$$t_2 - 25 = 2000$$t_2 = 2025^{\circ} C$Thus,the temperature of the filament when the bulb is turned $ON$ is $2025^{\circ} C$.

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