Project ForgeA simply-supported beam of span 1000 mm carries a 100 N load applied via a rigid offset bracket: the bracket attaches to the beam's axis 500 mm from the left support, then extends 100 mm further to the right where the 100 N load acts downward. The maximum bending moment in the beam, in Nm, is
- A25
- 30
- C35
- D60
Explanation
Transferring the 100 N load (whose true line of action is 100 mm to the right of the bracket's attachment point) to the beam's axis at x=500 mm gives an equivalent 100 N downward force PLUS a concentrated couple M=100×100=10,000 N·mm at that point. Reactions (equivalent to a 100 N load at x=600 mm): R1=40 N, R2=60 N. Bending moment just left of x=500: 40×500=20,000 N·mm; the applied couple then causes a jump to 30,000 N·mm just right of x=500, after which BM decreases linearly back to 0 at x=1000 (matching R2 there) — so the true maximum is 30,000 N·mm = 30 Nm, occurring immediately after the bracket attachment point.
Source: GATE ME 2007 (2007)
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