In the circuit diagrams (A, B, C and D) shown below, $\mathrm{R}$ is a high resistance and $\mathrm{S}$ is a…
In the circuit diagrams (A, B, C and D) shown below, $\mathrm{R}$ is a high resistance and $\mathrm{S}$ is a resistance of the order of galvanometer resistance G. The correct circuit, corresponding to the half deflection method for finding the resistance and figure of merit of the galvanometer, is the circuit labelled as:
(a)
(b)
(C)
(d)
Circuit A with $\mathrm{G}=\frac{\mathrm{RS}}{(\mathrm{R}-\mathrm{S})}$
Circuit B with $\mathrm{G}=\mathrm{S}$
Circuit $\mathrm{C}$ with $\mathrm{G}=\mathrm{S}$
Circuit $D$ with $\left.G=\frac{R S}{(R-S}\right)$
Solution
The correct circuit diagram is $D$ with galvanometer resistance
$
G=\frac{R S}{R-S}
$
