A galvanometer of resistance `G` is shunted by a resistance `S ohm`. To keep the main current in the circuit uncharged, the resistnace to be put in series with the galvonmeter

Options

A. `(G^2)/((S + G))`
B. `(G)/((S + G))`
C. `(S^2)/((S + G))`
D. `(SG)/((S + G))`

Answer

A

Explanation

`G = (GS)/(G + S) + R`
`R = (G^2)/(G + S)`.