The sensitivity of a galvanometer can be decreased by:

Explanation

Sensitivity of a galvanometer is defined as the deflection per unit current. Increasing the magnetic field or the number of turns in the coil increases the sensitivity, as both enhance the torque that causes deflection. Decreasing the length of the couple 'c' also increases sensitivity by reducing the counteracting torque. However, increasing the c/BAN ratio, where 'c' is a constant related to the coil's resistance, 'B' is the magnetic field, 'A' is the area of the coil, and 'N' is the number of turns, results in a decreased sensitivity by reducing the deflection per unit current.