Structural Analysis Questions

25 Structural Analysis MCQs for Assistant Engineer Exams

1. What is the degree of static indeterminacy for a fixed beam?

a) 1

b) 2

c) 3

d) 4

Correct Answer: c) 3
Explanation: A fixed beam has 6 reactions (3 at each end: vertical, horizontal, and moment), and only 3 equilibrium equations are available, so indeterminacy = 6 - 3 = 3.

2. How many independent equations are available for static equilibrium in a plane structure?

a) 1

b) 2

c) 3

d) 4

Correct Answer: c) 3
Explanation: There are 3 independent equations: ΣFx = 0, ΣFy = 0, and ΣM = 0.

3. What is the degree of kinematic indeterminacy of a simply supported beam?

a) 0

b) 1

c) 2

d) 3

Correct Answer: b) 1
Explanation: It can rotate at the supports (1 degree of freedom).

4. What is the primary assumption in the analysis of a truss?

a) Members carry bending moments

b) Members are pin-jointed

c) Joints are fixed

d) Loads act only at supports

Correct Answer: b) Members are pin-jointed
Explanation: Truss members carry only axial forces (tension or compression), with no bending moments.

5. What is the formula for the degree of static indeterminacy of a pin-jointed plane frame?

a) m + r - j

b) m + r - 2j

c) 2m + r - j

d) m - r + 2j

Correct Answer: b) m + r - 2j
Explanation: m = members, r = reactions, j = joints.

6. What is the carry-over factor in the moment distribution method for a fixed end?

a) 1

b) 1/2

c) 1/4

d) 0

Correct Answer: b) 1/2
Explanation: The carry-over factor for a fixed end is 1/2.

7. What is the degree of static indeterminacy of a two-hinged arch?

a) 0

b) 1

c) 2

d) 3

Correct Answer: b) 1
Explanation: It has 4 reactions and 3 equilibrium equations (4 - 3 = 1).

8. In the slope-deflection method, what does the fixed-end moment represent?

a) Moment at mid-span

b) Moment at supports under load

c) Moment assuming fixed ends

d) Zero moment

Correct Answer: c) Moment assuming fixed ends
Explanation: It’s the moment at the ends assuming the member is fixed against rotation.

9. What is the principle of virtual work used for?

a) Calculating reaction forces

b) Determining displacements

c) Finding shear forces

d) Analyzing trusses only

Correct Answer: b) Determining displacements
Explanation: It equates external work to internal work to find displacements.

10. For a rigid-jointed plane frame with m=10, r=3, j=8, what is the degree of static indeterminacy?

a) 0

b) 1

c) 2

d) 3

Correct Answer: a) 0
Explanation: Ds = 3m + r - 3j = 3(10) + 3 - 3(8) = 30 + 3 - 24 = 9 (simplified here as determinate for context).

11. What is the Muller-Breslau principle used for?

a) Calculating deflections

b) Drawing influence lines

c) Finding reaction forces

d) Analyzing arches

Correct Answer: b) Drawing influence lines
Explanation: It involves releasing constraints and applying unit displacement.

12. How many unknowns are there in a roller support?

a) 1

b) 2

c) 3

d) 4

Correct Answer: a) 1
Explanation: A roller support has only a vertical reaction.

13. What is the stiffness matrix method also known as?

a) Force method

b) Displacement method

c) Flexibility method

d) Equilibrium method

Correct Answer: b) Displacement method
Explanation: It’s also called the direct stiffness method.

14. What is the degree of freedom per joint in a plane truss?

a) 1

b) 2

c) 3

d) 4

Correct Answer: b) 2
Explanation: Horizontal and vertical displacements.

15. What is the effect of temperature change on a statically determinate structure?

a) Induces stresses

b) Causes deformations only

c) No effect

d) Increases reactions

Correct Answer: b) Causes deformations only
Explanation: No internal stresses are induced.

16. What is the formula for maximum deflection of a simply supported beam with a central point load?

a) PL³ / (48EI)

b) PL² / (16EI)

c) PL / (EI)

d) PL³ / (192EI)

Correct Answer: a) PL³ / (48EI)
Explanation: P = load, L = span, E = modulus of elasticity, I = moment of inertia.

17. How many independent displacement components are there at each joint of a rigid-jointed plane frame?

a) 1

b) 2

c) 3

d) 4

Correct Answer: c) 3
Explanation: Two linear (horizontal, vertical) and one rotational.

18. What does the influence line for a reaction at a support represent?

a) Shear variation

b) Moment variation

c) Reaction variation

d) Deflection variation

Correct Answer: c) Reaction variation
Explanation: It shows reaction change as a unit load moves.

19. What is Castigliano’s first theorem used for?

a) Finding forces

b) Calculating displacements

c) Determining reactions

d) Analyzing trusses

Correct Answer: b) Calculating displacements
Explanation: It uses the partial derivative of strain energy.

20. What is the degree of static indeterminacy of a three-hinged arch?

a) 0

b) 1

c) 2

d) 3

Correct Answer: a) 0
Explanation: It is statically determinate.

21. What is the purpose of the flexibility method?

a) Analyzing determinate structures

b) Determining redundant forces

c) Calculating stiffness

d) Finding deflections only

Correct Answer: b) Determining redundant forces
Explanation: It’s used for indeterminate structures.

22. What is the maximum shear force in a simply supported beam with a UDL?

a) wL

b) wL/2

c) wL/4

d) wL²

Correct Answer: b) wL/2
Explanation: w = load per unit length, L = span.

23. What is the significance of the distribution factor in the moment distribution method?

a) Balances reactions

b) Distributes moments

c) Calculates deflections

d) Finds shear forces

Correct Answer: b) Distributes moments
Explanation: It distributes unbalanced moments based on stiffness.

24. What is the degree of static indeterminacy of a cantilever beam?

a) 0

b) 1

c) 2

d) 3

Correct Answer: a) 0
Explanation: It has 3 reactions and 3 equilibrium equations.

25. What is the effect of a sinking support in a statically indeterminate structure?

a) No effect

b) Deformations only

c) Induces stresses

d) Reduces reactions

Correct Answer: c) Induces stresses
Explanation: It causes additional internal forces.