Q. A galvanometer has a resistance $G$ and a current $i_{g}$ flowing in it produces full scale deflection. $S_{1}$ is the value of the shunt which converts it into a ammeter or range 0 to $i\ \ and\ S_{2}$ is the value of the shunt for the range 0 to $2\ i$. The ratio $\frac{S_{1}}{S_{2}}\ $ is
A) $\left( \frac{2i - i_{g}}{i - i_{g}} \right)$
B) $\frac{1}{2}\ \left( \frac{i - i_{g}}{2i - i_{g}} \right)$
C) 2
D) 1
Explanation
(a) $S_{1} = \frac{i_{g}\ G}{i - i_{g}};S_{2} = \ \frac{i_{g}\ G}{2i - i_{g}};so,\frac{S_{1}}{S_{2}} = \left( \frac{2i - i_{g}}{i - i_{g}} \right)$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.