Explanation Shear stress at any point in a cross-section is given by the following formula: ${\rm{f}} = \frac{{{\rm{VQ}}}}{{{\rm{Ib}}}}$ Where, f = shear stress Q = First moment of area about the neutral axis of the area above the point where we want to calculate the shear stress Q = A × y V is Shear force y is the centroid of the area above the point where we want to calculate the shear stress measured from the neutral axis. A = Cross-sectional area above the point where we want to calculate the shear stress I = moment of inertia about the neutral axis b= width of the section where shear stress is to be calculated. Shear stress is zero at extreme fibres For a symmetric ‘I’ section, the intensity of shear stress is maximum at the centroid of the section which is neutral axis as shown in the figure.