1. For a cantilever beam, the span to effective depth ratio is generally restricted to
ⓐ. 7
ⓑ. 10
ⓒ. 15
ⓓ. 20
Correct Answer: 7
Explanation: For a cantilever beam, the span to effective depth ratio is generally restricted to a value of 7. This limitation helps maintain the stability and strength of the cantilevered structure.
2. In R.B. slab, the permissible compressive stress in bricks is generally taken as
ⓐ. 10 kg/cm²
ⓑ. 20 kg/cm²
ⓒ. 30 kg/cm²
ⓓ. 40 kg/cm²
Correct Answer: 10 kg/cm²
Explanation: In a Reinforced Brick (R.B.) slab, the permissible compressive stress in bricks is generally taken as 10 kg/cm². This value ensures the safe and efficient performance of the brick material in the slab structure.
3. The slope of weep hole is generally provided at (spacing- 1.5 to 3.0m)
ⓐ. 1 in 4
ⓑ. 1 in 8
ⓒ. 1 in 16
ⓓ. 1 in 32
Correct Answer: 1 in 8
Explanation: The slope of weep holes is generally provided at a ratio of 1 in 8. Weep holes with appropriate spacing and slope are used in retaining walls to facilitate drainage and prevent water buildup behind the wall.
4. Weep holes are provided in retaining and breast walls to
ⓐ. increase compaction
ⓑ. increase architectural beauty
ⓒ. drain off the water from the fillings
ⓓ. none of the above
Correct Answer: drain off the water from the fillings
Explanation: Weep holes are provided in retaining and breast walls to facilitate drainage and prevent water accumulation behind the walls. They allow water to escape, reducing the risk of hydrostatic pressure and potential damage to the structure.
5. In the case of the foundation of rigid base, the distribution pressure on the soil is
ⓐ. uniform
ⓑ. maximum bending moment
ⓒ. minimum in the central zone
ⓓ. none of the above
Correct Answer: uniform
Explanation: In the case of the foundation of a rigid base, the distribution pressure on the soil is generally uniform. This uniform distribution helps in preventing excessive settlement and ensures stability.
6. The minimum overall depth kept at the edge of R.C. footings is
ⓐ. 50 cm
ⓑ. 25 cm
ⓒ. 15 cm
ⓓ. 10 cm
Correct Answer: 15 cm
Explanation: The minimum overall depth kept at the edge of Reinforced Concrete (R.C.) footings is typically 15 cm. This depth provides adequate strength and support for the footing structure.
7. If a beam fails in bond, then
ⓐ. increase the depth of the beam
ⓑ. use thicker but fewer numbers of bars
ⓒ. use thinner but more numbers of bars
ⓓ. providing vertical stirrups
Correct Answer: use thicker but fewer numbers of bars
Explanation: If a beam fails in bond, one approach to address the issue is to use thicker but fewer numbers of bars. This helps enhance the bond strength between the concrete and the reinforcement.
8. The resistance offered to slipping of steel bars in concrete is due to
ⓐ. adhesion
ⓑ. frictional resistance
ⓒ. mechanical resistance
ⓓ. all of the above
Correct Answer: frictional resistance
Explanation: The resistance offered to slipping of steel bars in concrete is primarily due to frictional resistance between the steel and the surrounding concrete. Adhesion and mechanical resistance also play a role in preventing slippage.
9. When the material is loaded with tensile force at both ends, then the test is known as
ⓐ. tensile test
ⓑ. compressive test
ⓒ. shear test
ⓓ. all of the above
Correct Answer: tensile test
Explanation: When a material is loaded with tensile force at both ends, the test is known as a tensile test. This test is conducted to measure the material’s response to tensile stress and deformation.
10. The safe bond stress between concrete and steel is determined by
ⓐ. tensile test
ⓑ. compressive test
ⓒ. shear test
ⓓ. pull-out test
Correct Answer: pull-out test
Explanation: The safe bond stress between concrete and steel is determined by the pull-out test. This test assesses the bond strength between the concrete and the embedded steel reinforcement by applying a tensile force to the bar and measuring its resistance to pull-out.
11. The ratio left / b of the column is considered as a long column if its value is
ⓐ. 5
ⓑ. 10
ⓒ. 15
ⓓ. 20
Correct Answer: 15
Explanation: The ratio left / b of a column is considered as a long column if its value is greater than 12 to 15. This indicates that the effective length of the column in relation to its least lateral dimension is significant, leading to a long-column behavior.
12. The cover provided in the column having size less than 200 mm x 200 mm is
ⓐ. 15
ⓑ. 20
ⓒ. 25
ⓓ. 40
Correct Answer: 25
Explanation: The cover provided in the column with a size less than 200 mm x 200 mm is typically 25 mm. Cover is the protective layer of concrete that separates the reinforcement from the external environment, providing durability and corrosion resistance.
13. The types of failure occurring in a beam due to shear force is termed as
ⓐ. diagonal tension failure
ⓑ. flexural tension failure
ⓒ. diagonal compression failure
ⓓ. all of the above
Correct Answer: diagonal tension failure
Explanation: The types of failure occurring in a beam due to shear force are termed as diagonal tension failure. This failure mode involves the development of diagonal cracks in the tension zone of the beam.
14. Tensile strength of Fe415 is taken as
ⓐ. 415 N/mm²
ⓑ. 230 N/mm²
ⓒ. 145 N/mm²
ⓓ. all of the above
Correct Answer: 415 N/mm²
Explanation: The tensile strength of Fe415 steel is taken as 415 N/mm². This represents the maximum tensile stress that the steel can withstand.
15. An RCC element, 1 m deep and 0.5 m wide will require minimum reinforcement @ 1% of the gross sectional area, what will be the area of reinforcing bars?
ⓐ. 500 mm²
ⓑ. 1000 mm²
ⓒ. 5000 mm²
ⓓ. 50,000 mm²
Correct Answer: 5000 mm²
Explanation: The gross sectional area of the RCC element is 1 m and 0.5 m, m = 0.5 , m². The minimum reinforcement is 1% of this area, which is 0.01 times 0.5 , m² = 0.005 , m² = 5000 , mm².
16. In a singly reinforced beam (concrete), as the load increases
ⓐ. only concrete will resist tension
ⓑ. only steel bars will resist tension
ⓒ. both concrete and steel will resist tension
ⓓ. both concrete and steel will resist compression
Correct Answer: only concrete will resist tension
Explanation: In a singly reinforced beam, as the load increases, the concrete resists tension until it reaches its tensile strength. After that, the steel reinforcement takes over to resist tension.
17. Laps in bars are equal to
ⓐ. bond length
ⓑ. twice bond length
ⓒ. 1.5 to twice bond length
ⓓ. none of the above
Correct Answer: 1.5 to twice bond length
Explanation: The laps in bars, which refer to the overlapping of two reinforcing bars, are generally in the range of 1.5 to twice the bond length. This ensures proper transfer of stresses and maintains the integrity of the reinforcement.
18. The amount of reinforcement for main bars in a slab is based upon
ⓐ. maximum bending moment
ⓑ. minimum shear force
ⓒ. maximum shear force
ⓓ. minimum bending moment
Correct Answer: maximum bending moment
Explanation: The amount of reinforcement for main bars in a slab is based upon the maximum bending moment. This is because the main bars are primarily designed to resist bending stresses in the slab.
19. A column is considered as a long column if its slenderness ratio is more than
ⓐ. 28
ⓑ. 12
ⓒ. 20
ⓓ. 24
Correct Answer: 12
Explanation: A column is considered as a long column if its slenderness ratio (\(l / r\)) is more than 12. The slenderness ratio is the ratio of the effective length of the column to its least radius of gyration.
20. The states of concrete are
ⓐ. elastic and hardened state
ⓑ. elastic and plastic state
ⓒ. plastic and hardened state
ⓓ. none of the above
Correct Answer: plastic and hardened state
Explanation: The states of concrete include the plastic state (during mixing, placing, and compaction) and the hardened state (after curing and gaining strength). The plastic state refers to the moldable, fresh concrete, while the hardened state is the final, cured and set concrete.
21. A balanced design of a beam is a condition where the ….. stresses occurring are equal to the permissible stress.
ⓐ. least
ⓑ. average
ⓒ. greatest
ⓓ. none of these
Correct Answer: greatest
Explanation: In a balanced design of a beam, the maximum stresses occurring, whether in concrete or steel, are equal to the permissible stress. This means that both materials reach their maximum capacity simultaneously, resulting in a balanced condition.
22. The ultimate tensile strength of structural mild steel is about
ⓐ. 160 N/mm²
ⓑ. 260 N/mm²
ⓒ. 520 N/mm²
ⓓ. 420 N/mm²
Correct Answer: 420 N/mm²
Explanation: The ultimate tensile strength of structural mild steel is approximately 420 N/mm². This represents the maximum tensile stress that the steel can withstand before failure.
23. A reinforced concrete beam will crack if tensile stress set up in the concrete below the neutral axis is
ⓐ. less than the permissible stress
ⓑ. more than the permissible stress
ⓒ. equal to the permissible stress
ⓓ. any one of the above
Correct Answer: more than the permissible stress
Explanation: A reinforced concrete beam will crack if the tensile stress developed in the concrete below the neutral axis exceeds the permissible stress for concrete. Cracking occurs when the tensile stress reaches a critical value.
24. The moment of resistance of an under-reinforced section is computed on the basis of
ⓐ. compressive force developed in concrete
ⓑ. tensile force developed in steel
ⓒ. both of the above
ⓓ. none of the above
Correct Answer: tensile force developed in steel
Explanation: The moment of resistance of an under-reinforced section is primarily computed based on the tensile force developed in the steel reinforcement. The contribution of concrete in compression is also considered, but the tensile force in steel is a critical factor.
25. In a beam section, if the steel reinforcement is of such a magnitude that the permissible stresses in concrete and steel are developed simultaneously, the section is known as
ⓐ. balanced section
ⓑ. critical section
ⓒ. economical section
ⓓ. any one of the above
Correct Answer: any one of the above
Explanation: Such a section is known as a balanced section, a critical section, or an economical section. In this condition, both concrete and steel reach their permissible stresses simultaneously, leading to a balanced and efficient design.
26. A rigid frame is a structure composed of members which are connected by
ⓐ. a single rivet
ⓑ. rigid joints
ⓒ. simple bearing
ⓓ. none of the above
Correct Answer: rigid joints
Explanation: A rigid frame is a structure where the members are connected by rigid joints, allowing minimal rotation at the connections. This characteristic helps distribute moments and provides stability to the frame.
27. Which of the following factors influence the strength of concrete?
ⓐ. compaction
ⓑ. curing
ⓒ. water-cement ratio
ⓓ. all of the above
Correct Answer: all of the above
Explanation: All the mentioned factors—compaction during placement, proper curing after placement, and an appropriate water-cement ratio—influence the strength and durability of concrete. These factors play crucial roles in achieving the desired concrete properties.
28. What is the minimum period for which the lime concrete in the foundation be left wet without the construction of masonry over it?
ⓐ. 15 days
ⓑ. 12 days
ⓒ. 9 days
ⓓ. 7 days
Correct Answer: 7 days
Explanation: Lime concrete in foundations should be kept wet for a minimum period of 7 days without the construction of masonry over it. This ensures proper curing and development of strength in lime concrete.
29. Two layers of tensile reinforcement bars are placed in a flexural member in such a way that the effective depth would be
ⓐ. maximum
ⓑ. minimum
ⓒ. negative
ⓓ. zero
Correct Answer: minimum
Explanation: Placing two layers of tensile reinforcement bars in a flexural member in such a way that they are close to the tension face minimizes the effective depth. This arrangement helps in optimizing the use of reinforcement and improving the performance of the member.
30. For a reinforced concrete section, the shape of shear stress diagram is
ⓐ. wholly parabolic
ⓑ. wholly rectangular
ⓒ. parabolic above the neutral axis and rectangular below the neutral axis
ⓓ. rectangular above the neutral axis and parabolic below the neutral axis
Correct Answer: parabolic above the neutral axis and rectangular below the neutral axis
Explanation: In a reinforced concrete section, the shear stress diagram is typically parabolic above the neutral axis and rectangular below the neutral axis. This distribution of shear stress helps in understanding and designing for the shear forces in the structure.
31. The one-way slab is one
ⓐ. which is short and bends in two directions
ⓑ. the slab which bends only along one direction
ⓒ. reinforced in one direction only
ⓓ. all of the above
Correct Answer: the slab which bends only along one direction
Explanation: A one-way slab is designed to bend primarily in one direction, and its reinforcement is provided to resist the bending stresses in that direction.
32. In an over-reinforced concrete section, the failure starts at
ⓐ. compression face
ⓑ. tension face
ⓒ. neutral axis
ⓓ. diagonals
Correct Answer: compression face
Explanation: In an over-reinforced section, where the amount of steel is more than needed for balanced design, failure typically initiates in the compression zone.
33. The maximum strain in the tension reinforcement in the section of a flexural member at failure shall not be less than (if fy is the characteristic strength of steel and Es is the modulus of elasticity of steel)
ⓐ. 0.0020
ⓑ. fy/(1.15Es) + 0.002
ⓒ. fy/(1.15Es) + 0.003
ⓓ. 0.0300
Correct Answer: fy/(1.15Es) + 0.002
Explanation: The maximum strain in the tension reinforcement at failure is determined by the material properties of the steel and is often specified to ensure ductility and proper performance.
34. A flat slab is supported
ⓐ. on beams
ⓑ. on columns
ⓒ. on beams and columns
ⓓ. on columns monolithically built with slab
Correct Answer: on columns monolithically built with slab
Explanation: In a flat slab system, the slab is directly supported by columns that are monolithically connected with the slab, eliminating the need for beams.
35. If a beam is loaded transversely the maximum compressive stress develops on
ⓐ. top fibre
ⓑ. neutral axis
ⓒ. bottom fibre
ⓓ. every cross-section
Correct Answer: top fibre
Explanation: In a simply supported beam loaded transversely, the maximum compressive stress develops at the top fiber of the beam.
36. The ratio of ultimate strength to working stress is
ⓐ. distribution factor
ⓑ. load factor
ⓒ. safety factor
ⓓ. shape factor
Correct Answer: safety factor
Explanation: The ratio of ultimate strength to working stress is commonly known as the safety factor, representing the factor by which the design strength is reduced to ensure the safety and reliability of the structure.
37. In a doubly reinforced section, the required compressive reinforcement is provided for the
ⓐ. bending moment in excess of Mlim of singly reinforced section
ⓑ. bending moment equal to Mlim of singly reinforced section
ⓒ. shear force of the beam section
ⓓ. shear force in excess of the Vlim of single reinforced section
Correct Answer: bending moment in excess of Mlim of singly reinforced section
Explanation: In a doubly reinforced section, extra compressive reinforcement is provided to handle bending moments beyond the limit of a singly reinforced section.
38. Maximum value of bond stress of an RCC section for a concrete mix of M20 for the limit state method of design should be (for plain bars)
ⓐ. 1.2
ⓑ. 1.4
ⓒ. 1.5
ⓓ. 1.8
Correct Answer: 1.2
Explanation: The maximum value of bond stress is often limited to ensure the integrity of the bond between the concrete and the reinforcing bars.
39. Large size aggregate is better in yield high strength but in no case greater than
ⓐ. 2/3 of the minimum thickness of the member
ⓑ. 1/3 of the minimum thickness of the member
ⓒ. 3/4 of the minimum thickness of the member
ⓓ. 1/4 of the minimum thickness of the member
Correct Answer: 1/4 of the minimum thickness of the member
Explanation: The size of the aggregate is limited to avoid issues such as honeycombing and to ensure workability. In no case should the size be greater than 1/4 of the minimum thickness of the member.
40. The effective span of a simply supported slab is
ⓐ. clear span plus the effective depth of the slab
ⓑ. span between outer faces of two walls
ⓒ. distance between the center of bearing
ⓓ. none of the above
Correct Answer: clear span plus the effective depth of the slab
Explanation: The effective span of a simply supported slab is the clear span plus the effective depth of the slab, taking into account the supporting conditions.
41. If the slenderness ratio for a column is 100 then the column is said to be
ⓐ. long
ⓑ. medium
ⓒ. short
ⓓ. none of the above
Correct Answer: long
Explanation: The slenderness ratio is a measure of how slender or stocky a column is. If the slenderness ratio is high, the column is considered long.
42. For an RCC section, select the most true statement from the following
ⓐ. Bond stress = Bond Load/X-area of rebar
ⓑ. In a doubly reinforced section, rebars are placed at two tiers on the tensile face
ⓒ. Shear stress (π) is perpendicular to the material cross-section
ⓓ. Shear stress in rebar is calculated as (π) = Shear force/Nominal surface area of rebar
Correct Answer: Bond stress = Bond Load/X-area of rebar
Explanation: Bond stress is the force exerted between the reinforcing bar and the surrounding concrete per unit area of the bar’s surface.
43. Spacing of stirrups in a rectangular beam is
ⓐ. kept constant throughout the length
ⓑ. increased towards the center of the beam
ⓒ. increased at the ends
ⓓ. increased at the center of the beam
Correct Answer: increased towards the center of the beam
Explanation: The spacing of stirrups in a rectangular beam is often increased towards the center to provide adequate shear reinforcement where the shear forces are higher.
44. The amount of reinforcement for main bars in a slab is based upon
ⓐ. minimum bending moment
ⓑ. maximum bending moment
ⓒ. minimum shear stress
ⓓ. maximum shear force
Correct Answer: maximum bending moment
Explanation: The amount of reinforcement for main bars in a slab is based on the maximum bending moment to ensure that the slab can resist the applied loads.
45. The effective width of a column strip of a flat slab is
ⓐ. one-fourth the width of the panel
ⓑ. half the width of the panel
ⓒ. radius of the column
ⓓ. diameter of the column
Correct Answer: half the width of the panel
Explanation: The effective width of a column strip in a flat slab is typically taken as half the width of the panel, considering the distribution of loads and moments.
FAQs on Structural Design MCQs for Civil Engineers
▸ What are the fundamental principles of structural design?
The fundamental principles of structural design include understanding the load distribution, material properties, structural analysis, and ensuring stability and safety. Structural engineers must apply principles of statics, dynamics, and material mechanics to design structures that can safely carry loads and resist environmental forces.
▸ How do structural engineers ensure the safety of a building design?
Structural engineers ensure the safety of a building design by performing rigorous structural analysis to assess loads and stresses. They use codes and standards to guide their design, conduct safety checks, and often use software tools to simulate various conditions. The design must consider factors such as load-bearing capacity, material strength, and potential environmental impacts.
▸ What is the significance of load calculations in structural design?
Load calculations are crucial in structural design as they determine the amount of stress and strain that different parts of a structure will experience. Accurate load calculations ensure that the structure can support the expected loads, including live loads, dead loads, wind loads, and seismic loads, thus preventing potential failures and ensuring safety.
▸ How does material selection impact structural design?
Material selection significantly impacts structural design as different materials have varying strengths, durability, and properties. Engineers choose materials based on factors like load-bearing capacity, environmental resistance, cost, and aesthetics. Proper material selection ensures that the structure meets performance requirements and maintains safety and longevity.
▸ What role does structural analysis play in designing bridges?
Structural analysis is critical in bridge design as it helps engineers understand how different forces affect the bridge. It involves analyzing the effects of traffic loads, wind, seismic activity, and other factors. Accurate analysis ensures that the bridge can safely support these forces while maintaining stability and durability over time.
▸ What are some common structural design software tools used by engineers?
Common structural design software tools used by engineers include AutoCAD for drafting, SAP2000 for structural analysis, ETABS for building design, and STAAD.Pro for multi-disciplinary analysis. These tools help engineers model structures, perform complex calculations, and ensure compliance with design codes.
▸ How do seismic codes affect structural design?
Seismic codes affect structural design by providing guidelines to ensure structures can withstand earthquakes. These codes require engineers to incorporate specific design features such as reinforcement, flexible joints, and base isolation to absorb and dissipate seismic energy, minimizing damage and protecting occupants during seismic events.
▸ What are the best practices for designing earthquake-resistant structures?
Best practices for designing earthquake-resistant structures include using high-quality materials, ensuring proper reinforcement, designing flexible connections, and incorporating base isolators. Engineers also follow seismic codes and guidelines to enhance the structure’s ability to absorb and dissipate seismic forces, reducing the risk of damage during an earthquake.
▸ What factors should be considered when designing multi-story buildings?
When designing multi-story buildings, factors to consider include load distribution, lateral stability, structural connections, and material properties. Engineers must account for the increased loads on lower floors, ensure proper vertical and horizontal load transfer, and address challenges related to wind, seismic forces, and building settlement.
▸ How can I find online quizzes and practice questions for structural design?
You can find online quizzes and practice questions for structural design on educational websites such as https://gkaim.com. These resources offer a variety of practice materials to help you test your knowledge and prepare for exams related to structural engineering.
