Q1: In the zone of R.C.C. beam where shear stress is less than 5 kg/cm², nominal reinforcement is provided at a pitch of

ANS:C - lever arm of the section

In reinforced concrete (R.C.C.) beams, nominal shear reinforcement, often in the form of stirrups or inclined bars, is provided to enhance the shear capacity of the beam in regions where the shear stress exceeds certain limits. When the shear stress is less than 5 kg/cm², which is considered a low shear stress level, nominal reinforcement may not be necessary for shear reinforcement according to some design codes and standards. However, if designers choose to provide nominal shear reinforcement in this low shear stress zone for reasons such as improved ductility or to control cracking, they typically place it at a conservative spacing. This spacing is often determined based on engineering judgment rather than strict design requirements. Among the options provided, the most common practice for the pitch of nominal reinforcement in a zone where shear stress is less than 5 kg/cm² is: One and a half times the lever arm of the sectionOne and a half times the lever arm of the section Providing nominal reinforcement at a pitch of one and a half times the lever arm of the section ensures that there is some additional reinforcement to resist shear, albeit at wider spacing compared to regions experiencing higher shear stresses. It's essential to note that the specific detailing and spacing of nominal shear reinforcement may vary based on project requirements, design preferences, and applicable design codes and standards. Always refer to the relevant design standards and consult with a structural engineer to determine the appropriate reinforcement detailing for R.C.C. beams.