[amp_mcq option1=”Supports” option2=”Mid span” option3=”simply supported beams carrying U.” option4=”Quarter span” correct=”option1″]
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.