Question:-
A horizontal beam carrying uniformly distributed load is supported with equal overhangs as shown in the given figure resultant bending moment at the mid-span shell be zero if a/b is
Option (A)
3/4
Option (B)
2/3
Option(C)
1/2
Option(D)
1/3
Correct Option:
(C)
Question Solution:

Let Load is W N/m
Find reaction forces R1 and R2
\ R1 + R2 = w(2a + b) .......(1)
taking moment about R1
- (Wa2 / 2) + (W(a+b)2 / 2) – R2 x b = 0
\ R2 = W{a+(b/2)} = R1
Bending moment at mid-span
[W{a+(b/2)}2 / 2] – W(a+b/2) x (b/2) = 0
a+(b/2) = b
\ a/b = 1/2
question-answer-faq-9346