A helical gear with $20^{\circ}$ pressure angle and $30^{\circ}$ helix angle mounted at the mid-span of a shaft that is supported between two bearings at the ends. The nature of the stresses induced in the shaft is

1. normal stress due to bending only
2. normal stress due to bending in one plane and axial loading; shear stress due to torsion
3. normal stress due to bending in two planes and axial loading; shear stress due to torsion
4. normal stress due to bending in two planes; shear stress due to torsion