The current sensitivity of a moving coil galvanometer (deflection per unit current) is:

1. From equilibrium, $\phi = \dfrac{NAB}{k}I$. 2. Current sensitivity is defined as the deflection per unit current, $\dfrac{\phi}{I}$. 3. Dividing gives $\dfrac{\phi}{I} = \dfrac{NAB}{k}$. 4. The factor $1/R$ appears in voltage sensitivity, not current sensitivity. _Source: syllabus Physics Ch 4 "Moving Charges and Magnetism", p.160_