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Sabu

Jun 24, 2014

# An electric bulb is rated 220V and 100W. when it is operated on 110V, what will be the power consumed?

An electric bulb is rated 220V and 100W. when it is operated on 110V, what will be the power consumed?

Janhavi Govinda rao

P = V2/R   If V = 220 V we have 100 W = 2202/R R = 2202/100 Ω = 484 Ω. This is the resistance of the bulb. When V = 110 V, power consumed =  V2/R = 1102 /484 = 25 W.

Syeda

Answer.     P = V2/R   If V = 220 V we have 100 W = 2202/R R = 2202/100 Ω = 484 Ω. This is the resistance of the bulb. When V = 110 V, power consumed =  V2/R = 1102 /484 = 25 W.

Member since Apr 1, 2017

$\fn_cm \\Solution:\\ Given:\\ Power\ (P)=100W\\ Voltage=220V\\\\ The\ power\ consumption\ of\ an\ electric\ bulb \ is\ given \ by:\\\\ P=\frac{V^2}{R}\ \ \ Here,\ P\ is\ the\ power,\ \ V\ is\ the\ voltage\ and\ R\ is\ the\ resistance\\\\ \Rightarrow 100=\frac{220^2}{R}\\\\ \Rightarrow R=\frac{220\times220}{100}\\\\ \therefore R=484\ Ohm\\\\\\ When\ the\ same\ bulb\ is\ used\ across\ the\ voltage\ of\ 110 V, then\ power\ is\ given\ by:\\ \Rightarrow P=\frac{V^2}{R}\\\\ \Rightarrow P=\frac{110^2}{484}=\frac{110\times110}{484}\\\\ \therefore P=25\ watt.$

Member since Apr 1, 2017

$\fn_cm \\Solution:\\ The\ power\ consumption\ of\ an\ Electric\ bulb\ is\ given\ by:\\\\ P=\frac{V^2}{R} \ \ \ Where\ P\ is\ the\ power,\ V\ is\ the\ voltage\ and\ R \ is\ the\ resistance\\\\\\ The\ power\ consumption\ of\ an\ Electric\ bulb\ is\ rated\ 220V\ and\ 100W:\\\\ \Rightarrow 100=\frac{220^2}{R}\\\\\\ \Rightarrow R=\frac{220\times220}{100}\\\\\\ \therefore R=484\ Ohm\\\\\\ The\ power\ consumption\ of\ an\ Electric\ bulb\ is\ operated\ on\ 110V:\\\\ \Rightarrow P=\frac{110^2}{484}\\\\\\\ \Rightarrow P=\frac{110\times10}{484}\\\\\\ \therefore P=25W$
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