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

Answer

D

Explanation

Current will be unchanged if resistance remains same so
`G=(GS)/(G+S)+R` ltBRgt `implies R=G-(GS)/(G+S)`
= `(G^(2))/(G+S)`