Q1: Distribution of shear intensity over a rectangular section of a beam, follows :

ANS:C - a parabolic curve

In some advanced structural analysis or design scenarios, especially for irregular or non-prismatic beam sections, the distribution of shear intensity over a rectangular section of a beam might approximately follow a parabolic curve. A parabolic curve implies that the shear stress varies non-linearly across the depth of the beam. At the top and bottom surfaces, the shear stress is minimal (typically zero), and it increases gradually towards the neutral axis, reaching a maximum value at the neutral axis. Beyond the neutral axis, the shear stress decreases symmetrically, forming a curve that resembles a parabola. This type of shear stress distribution might occur in specific cases where the beam's geometry, loading, or boundary conditions result in complex stress distributions. However, it's essential to note that the shear stress distribution in most beams with rectangular cross-sections tends to be more linear than parabolic. While a linear distribution is more common and simpler to analyze, the parabolic curve distribution may be encountered in specialized analyses or under specific loading and support conditions.