An electric bulb is rated $60\,W$, $220\,V$. The resistance of its filament is ............. $\Omega$
A$708$
B$870$
C$807$
D$780$
AIPMT 1994, Easy
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C$807$
c (c) $ R = \frac{{{V^2}}}{P} = \frac{{{{(220)}^2}}}{{60}} = 807\,\Omega $
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