If the galvanometer $G$ does not show any deflection in the circuit shown, the value of $R$ is given

Question

If the galvanometer $G$ does not show any deflection in the circuit shown, the value of $R$ is given by\

Professor PC Thomas Classes · Answer

(a) : Since galvanometer shows no deflection, thus voltage across $R$ is 2 V .\ Now, voltage across $R$ is, $V=\frac{10 R}{400+R}$\ or $\quad 2=\frac{10 R}{400+R} \Rightarrow R=100 \Omega$