Design of R.C.C. simply supported beams carrying U.D.L. is based on the resultant B.M. at A. Supports B. Mid span C. Every section D. Quarter span

The correct answer is: A. Supports

The design of R.C.C. simply supported beams carrying U.D.L. is based on the resultant B.M. at supports. This is because the maximum bending moment in a simply supported beam occurs at the supports. The bending moment at any section of the beam can be calculated by using the following formula:

$M = \frac{wl}{2}(1 – \frac{x}{l})$

where:

• $M$ is the bending moment at the section
• $w$ is the uniform load
• $l$ is the span of the beam
• $x$ is the distance from the section to the left support

The maximum bending moment occurs when $x = 0$, which is at the left support. Therefore, the design of R.C.C. simply supported beams carrying U.D.L. is based on the resultant B.M. at supports.

The other options are incorrect because:

• The bending moment at mid-span is not the maximum bending moment.
• The bending moment at every section is not the maximum bending moment.
• The bending moment at quarter span is not the maximum bending moment.