Question

The resistance of uniform wire $\text{AB}$ is $9\Omega$. Find the resistance of part $\text{BC}$ (in $\Omega .$) For which galvanometer $\text{G}$ will show zero deflection

Answer 1

Potential difference across $AC$ is zero

$5-2I=0I=2.5\text{A}$

Let resistance of part $BC=R$

Using $KVL$,

$10+5-2I-IR-I=0$

$R=3\Omega$