A homogeneous simply supported prismatic beam of width B, depth D and span L is subjected to a concentrated load of magnitude P. The load can be placed anywhere along the span of the beam. The maximum flexural stress developed in beam is
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$\frac{2}{3} \frac{PL}{BD^2}$
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$\frac{3}{4} \frac{PL}{BD^2}$
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$\frac{4}{3} \frac{PL}{BD^2}$
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$\frac{3}{2} \frac{PL}{BD^2}$
D
Correct answer
Explanation
For a simply supported beam with a central point load P, the maximum bending moment is M = PL/4. The maximum flexural stress is sigma = M*y/I = (PL/4) * (D/2) / (B*D^3/12) = (PL*D/8) * (12/B*D^3) = 1.5 * PL / (B*D^2).