When a current of 1 Ampere is passed through a galvanometer coil, it is deflected through 20◦. But when it is shunted by a resistance of 12 Omega the same current produces a deflection of 5◦. The resistance of the galvanometer is

Options

A. `12Omega`
B. `20Omega`
C. `36Omega`
D. `40Omega`

Answer

C

Explanation

`thetaproptoI therefore I_g/I=5/(20)=1/4=1/n therefore S=G/(n-1) therefore 12=G/(4-1) therefore G=12 xx 3=36 Omega`