An electric bulb is rated $220 \mathrm{~V} ; 11 \mathrm{~W}$. The resistance of its filament when it

Question

An electric bulb is rated $220 \mathrm{~V} ; 11 \mathrm{~W}$. The resistance of its filament when it glows with a power supply of 220 V is\

Professor PC Thomas Classes · Answer

(a): Given, $V=220 \mathrm{~V}, P=11 \mathrm{~W}$ \As, $P=\frac{V^{2}}{R} \Rightarrow R=\frac{V^{2}}{P}=\frac{220 	imes 220}{11}=4400 \Omega$\