Three identical bulbs are connected as shown in figure. When switch $S$ is closed, the power consumed in bulb $B$ is $P$. What will be the power consumed by the same bulb when switch $S$ is opened?
A$\frac{9 P}{4}$
B$\frac{16 P}{9}$
C$\frac{9 P}{16}$
D$\frac{4 P}{9}$
Medium
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A$\frac{9 P}{4}$
a (a)
$P=\left(\frac{E}{2 R}\right)^2 R$
$P=\frac{E^2}{4 R}$
When $K$ is closed
$i=\frac{2 E}{3 R}$
$P^{\prime}=\frac{E^2}{9 R^2} \cdot R$
$P^{\prime}=\frac{E^2}{9 R}$
$\frac{P}{P^{\prime}}=\frac{9}{4}$
$P^{\prime}=\frac{4 P}{9}$
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