On giving $220\,V$ to a resistor the power dissipated is $40\,W$ then value of resistance is ............... $\Omega$
A$1210$
B$2000$
C$1000$
D
None of these
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A$1210$
a (a) $P = \frac{{{V^2}}}{R} \Rightarrow R = \frac{{{V^2}}}{P} = \frac{{{{(220)}^2}}}{{40}} = 1210\,\Omega $
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