Question

If deflection of galvanometer is zero, then value of E is

Answer 1

$18=i_1[1+6+2]\Rightarrow i_1=2A$
$i_2=\frac{(15-E)}{10}-\left(1\right)$
For zero deflection of galvanometer
$V_{AB}=V_{CD}\Rightarrow 6i_1=15-5i_2$
$6\times 2=15-5i_2\Rightarrow i_2=\frac{3}{5}-\left(2\right)$
By (1) & (2)
$\frac{15-E}{10}=\frac{3}{5}\Rightarrow E=15-6\Rightarrow E=9V$