1. When analyzing a truss using the method of joints, which of the following is a basic
assumption?
A. All joints are perfectly rigid
B. All loads are concentrated at the joints
C. Members are only subject to axial forces
D. Each joint can rotate independently
Answer: C) Members are only subject to axial forces
Rationale: The method of joints assumes that truss members are idealized as being subjected
only to axial forces (tension or compression), ignoring bending and torsion.
2. When calculating the internal forces in a truss using the method of joints, what equilibrium
equation is typically used?
A. ΣFy=0\Sigma F_y = 0ΣFy=0 and ΣFx=0\Sigma F_x = 0ΣFx=0
B. ΣM=0\Sigma M = 0ΣM=0
C. ΣFx=0\Sigma F_x = 0ΣFx=0 only
D. ΣMy=0\Sigma M_y = 0ΣMy=0
Answer: A) ΣFy=0\Sigma F_y = 0ΣFy=0 and ΣFx=0\Sigma F_x = 0ΣFx=0
Rationale: At each joint, the forces in the horizontal and vertical directions must balance, so both
ΣFx=0\Sigma F_x = 0ΣFx=0 and ΣFy=0\Sigma F_y = 0ΣFy=0 are used.
,3. Which method is commonly used for analyzing trusses?
A. Moment-curvature method
B. Direct stiffness method
C. Method of joints
D. Bending moment distribution method
Answer: C) Method of joints
Rationale: The method of joints is one of the simplest and most common methods used to
analyze trusses, focusing on equilibrium at each joint.
4. If a truss has 6 joints and 9 members, how many reactions will the truss have at the supports in
a 2D plane?
A. 1
B. 2
C. 3
D. 4
Answer: B) 2
Rationale: Using the equation m=2j−3m = 2j - 3m=2j−3, we can calculate the number of
members for a stable truss. With 6 joints, the number of members needed for stability is
2×6−3=92 \times 6 - 3 = 92×6−3=9, which implies that there are two reactions at the supports.
, 5. In a simple truss, how many reactions can be expected at the supports?
A. 1
B. 2
C. 3
D. 4
Answer: B) 2
Rationale: A simple truss typically has two reactions at the supports—one vertical and one
horizontal (depending on the support conditions).
6. What does the "zero-force member" rule in trusses indicate?
A. A member is under no load
B. A member is not connected to any joint
C. A member does not carry any internal force in certain conditions
D. A member is always under tension
Answer: C) A member does not carry any internal force in certain conditions
Rationale: Zero-force members are determined by looking at joints with two non-collinear
members and no external load or reaction. These members do not carry internal force under these
conditions.
7. Which of the following is an appropriate method for analyzing the forces in a truss with more
than three members?
assumption?
A. All joints are perfectly rigid
B. All loads are concentrated at the joints
C. Members are only subject to axial forces
D. Each joint can rotate independently
Answer: C) Members are only subject to axial forces
Rationale: The method of joints assumes that truss members are idealized as being subjected
only to axial forces (tension or compression), ignoring bending and torsion.
2. When calculating the internal forces in a truss using the method of joints, what equilibrium
equation is typically used?
A. ΣFy=0\Sigma F_y = 0ΣFy=0 and ΣFx=0\Sigma F_x = 0ΣFx=0
B. ΣM=0\Sigma M = 0ΣM=0
C. ΣFx=0\Sigma F_x = 0ΣFx=0 only
D. ΣMy=0\Sigma M_y = 0ΣMy=0
Answer: A) ΣFy=0\Sigma F_y = 0ΣFy=0 and ΣFx=0\Sigma F_x = 0ΣFx=0
Rationale: At each joint, the forces in the horizontal and vertical directions must balance, so both
ΣFx=0\Sigma F_x = 0ΣFx=0 and ΣFy=0\Sigma F_y = 0ΣFy=0 are used.
,3. Which method is commonly used for analyzing trusses?
A. Moment-curvature method
B. Direct stiffness method
C. Method of joints
D. Bending moment distribution method
Answer: C) Method of joints
Rationale: The method of joints is one of the simplest and most common methods used to
analyze trusses, focusing on equilibrium at each joint.
4. If a truss has 6 joints and 9 members, how many reactions will the truss have at the supports in
a 2D plane?
A. 1
B. 2
C. 3
D. 4
Answer: B) 2
Rationale: Using the equation m=2j−3m = 2j - 3m=2j−3, we can calculate the number of
members for a stable truss. With 6 joints, the number of members needed for stability is
2×6−3=92 \times 6 - 3 = 92×6−3=9, which implies that there are two reactions at the supports.
, 5. In a simple truss, how many reactions can be expected at the supports?
A. 1
B. 2
C. 3
D. 4
Answer: B) 2
Rationale: A simple truss typically has two reactions at the supports—one vertical and one
horizontal (depending on the support conditions).
6. What does the "zero-force member" rule in trusses indicate?
A. A member is under no load
B. A member is not connected to any joint
C. A member does not carry any internal force in certain conditions
D. A member is always under tension
Answer: C) A member does not carry any internal force in certain conditions
Rationale: Zero-force members are determined by looking at joints with two non-collinear
members and no external load or reaction. These members do not carry internal force under these
conditions.
7. Which of the following is an appropriate method for analyzing the forces in a truss with more
than three members?
