What will happen, if the magnetic field in moving coil galvanometer is non radial
In a radial magnetic field, the plane of the coil is always parallel to the magnetic lines of force,all the time irrespective of the position of the coil.
For any moving coil galvanometer we know that the deflection caused is directly proportional to the current flowing through it.
If the magnetic field is non radial, the deflection produced in the coil is not directly proportional to the current passing through the galvanometer. This will result in distorting the linear scale of measurement. Thus the linear scale cannot be used for the current measurement.