A truss is completely analysed when:
Try it first: pick an option, then read the explanation.
Asked in SSC JE 03/03/2017 (Morning)
Detailed Explanation
Analysing a truss means finding all the unknowns: the support reactions and the axial force in every member.
Why “The direct stresses (forces) in all the members are found” Is Correct
Reactions are only the first step; equilibrium is the tool used, not the result. The analysis is complete only when the forces (direct stresses) in all members are known, since those are what the members are designed for. So the best answer is (a).
Disputed answer: the book's printed key gives (c) ‘the equilibrium is satisfied’. Equilibrium must hold at every joint, but satisfying it is the means; the standard textbook statement is that a truss is completely analysed when the forces in all its members are determined.
Why the Other Options Are Wrong
- B. All the external reaction components are determined: Reactions are needed, but member forces are still unknown at that stage.
- C. The equilibrium is satisfied: Printed in the book's key, but equilibrium is the method; the analysis ends with all member forces known.
- D. None of these: Option (a) is correct.
Key Point
Truss analysis complete = all member forces (and reactions) known.
Key Concepts for Students
- Member forces are reported as tension (+) or compression (−).
- Method of joints gives all member forces systematically.
- Design then sizes each tie for strength and each strut for buckling.
Practice more: this is question 26 in Beams and Trusses MCQs – Part 2. Try the whole set and check every answer instantly.