Two electric bulbs rated ${P_1}\,watt$ $V\, volts$ and ${P_2}\, watt$ $V\, volts$ are connected in parallel and $V\, volts$ are applied to it. The total power will be
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If resistances of bulbs are ${R_1}$ and ${R_2}$ respectively then in parallel
$\frac{1}{{{R_P}}} = \frac{1}{{{R_1}}} + \frac{1}{{{R_2}}}$$ \Rightarrow $ $\frac{1}{{\left( {\frac{{{V^2}}}{{{P_p}}}} \right)}} = \frac{1}{{\left( {\frac{{{V^2}}}{{{P_1}}}} \right)}} + \frac{1}{{\left( {\frac{{{V^2}}}{{{P_2}}}} \right)}}$
$ \Rightarrow $ ${P_P} = {P_1} + {P_2}$
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