JEE Main · 2022 · 28 Jul 2022 · Shift 1 · Current Electricity

Current sensitivity of a galvanometer is $S_i=\frac{d\theta }{di}=\frac{NAB}{K}$, where $N$ is number of turns, $A$ is coil area, $B$ is magnetic field, and $K$ is torsional constant. To increase $S_i$, we can increase $N$, $A$, or $B$, or decrease $K$. From the options: (B) increasing $B$ increases $S_i$, and (D) decreasing $K$ increases $S_i$. Thus (B) and (D) are correct.