In the circuit shown the cells $A$ and $B$ have negligible resistances. For $V_{A}=12 \mathrm{~V}, R

Question

In the circuit shown the cells $A$ and $B$ have negligible resistances. For $V_{A}=12 \mathrm{~V}, R_{1}=500 \Omega$ and $R=100 \Omega$ the galvanometer ( $G$ ) shows no deflection. The value of $V_{B}$ is\

Professor PC Thomas Classes · Answer

(b) : Since the galvanometer shows no deflection so current will flow as shown in the figure.\ Current, $I=\frac{V_{A}}{R_{1}+R}=\frac{12 \mathrm{~V}}{(500+100) \Omega}=\frac{12}{600} \mathrm{~A}$\ $V_{B}=I R=\left(\frac{12}{600} \mathrm{~A}ight)(100 \Omega)=2 \mathrm{~V}$\