WAEC Physics 2022 Paper

Concept:The deflection of a moving coil galvanometer depends on the torque acting on the coil, which increases with the number of turns.Explanation:When current flows through the coil, the deflecting torque is given by $\tau = n B A I$.Here, $n$ is the number of turns, $B$ is the magnetic field, $A$ is the area of the coil, and $I$ is the current.By increasing the number of turns $n$, the torque produced for the same current becomes larger.A larger torque causes a greater deflection of the pointer.Thus, the galvanometer can detect smaller currents, meaning its sensitivity increases.Answer:B. increase the sensitivity of the galvanometer