Structural Analysis Multiple Choice Questions on “Sections Method Numericals”.
1. Method of the section for determinate truss analysis is time effective.
a) True
b) False
Answer: a
Clarification: Method of the section does not require the calculation of forces in the member prior to it. To compute force in any member, we cut the section and establish equilibrium conditions and hence it is time effective method.
2. To find the forces in the vertical member, preferable equilibrium equations are __________
a) ∑H = 0 & ∑M =0
b) ∑H = 0 & ∑V = 0
c) ∑H = 0, ∑V = 0 & ∑M = 0
d) ∑V = 0 & ∑M = 0
Answer: d
Clarification: Vertical unknowns at a particular selection should be preferably solved for ∑V = 0 first and later for ∑M = 0. Vertical Member does not have possesses any horizontal component of the forces hence ∑H = 0 is irrelevant to the context.
3. What is the force in member CG?
a) 0
b) W
c) W/2
d) W/√2
Answer: d
Clarification: ∑V = 0 & ∑M = 0
W/2 = FCG SIN 45°
FCG = W/√2.
4. What is the force in member CD?
a) 0
b) W (Compressive)
c) W (Tensile)
d) W/2 (Compressive)
Answer: b
Clarification: ∑MG = 0
FCD X L + (W/2) X 2L = 0
FCD = W (Compressive).