Question

Consider a $72\text{cm}$ long wire $AB$ as shown in the figure. The galvanometer jockey is placed at $P$ on $AB$ at a distance of $x\text{cm}$ from $A$. The galvanometer shows zero deflection. The value of $x$, to the nearest integer, is _____.

Answer 1

At balanced condition,

$\Rightarrow \frac{x}{12}=\frac{72-x}{6}$

$\Rightarrow 6x=12(72-x)$

$\Rightarrow 18x=864$

$\Rightarrow x=48\text{cm}$