If $X, Y$ and $Z$ in figure are identical lamps, which of the following changes to the brightnesses of the lamps occur when switch $S$ is closed?
A$X$ stays the same, $Y$ decreases
B$X$ increases, $Y$ decreases
C$X$ increases, $Y$ stays the same
D$X$ decreases, $Y$ increases
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B$X$ increases, $Y$ decreases
b Resistance of circuit decreases that increases current through $x$. So its brightness increases. Volttage across $Y$ decreases so it brightness will decreases.
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