A galvanometer of resistance G , is shunted by a resistance S . To keep the main current in the circuit unchanged, the resistance to be connected in series with the galvanometer is

Step-by-step solution

Given, galvanometer resistance, R_G=G and shunt resistance, R_S=S , Let the series resistance is R , so the net resistance of circuit after connected R , Since, it is given that the current should not change. So, it should be G , From Eq. (i) and (ii), we get aligned G & =R+ G S G+S R & =G- G S G+S R= G^2 G+S aligned Hence, the correct option is (a).