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GATE 2018 CE (CE2) – Question 14

Engineering Mechanics · Internal forces in structures · 1 mark · Multiple choice

All members of the planar truss shown have the same cross-sectional area A and elastic modulus E. For the loads shown, which statement correctly describes member forces?

Diagram for GATE 2018 CE (CE2) question 14
  1. 3 tension members and 2 compression members
  2. 2 tension, 2 compression and 1 zero-force member
  3. 2 tension, 1 compression and 2 zero-force members
  4. 2 tension and 3 zero-force members

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Show answer and explanation

Correct answer: (D) 2 tension and 3 zero-force members

Explanation

At the upper-left joint, the horizontal applied force is balanced by tension P in the top member, and the left vertical member carries zero force. At the lower-right joint, the bottom member carries tension P and the right vertical member is zero. Equilibrium at the upper-right joint then makes the diagonal zero. Thus two members are in tension and three have zero force (D).