RCC Short Notes & 50 MCQs for MP Sub Engineer Civil | LSM, WSM & RCC Beam

RCC Short Notes + 50 MCQs (English)

Basic Concepts • LSM • WSM • Singly & Doubly Reinforced Beams • IS 456:2000

Based on recurring PYQ patterns of SSC JE / RRB JE / MP Sub Engineer Civil

What is RCC?

RCC stands for Reinforced Cement Concrete. Concrete is strong in compression but weak in tension. Steel reinforcement is provided to resist tensile stresses.

Exam Point: Concrete mainly resists compression; steel mainly resists tension.

1. Basic Concepts

• Cement, Fine Aggregate, Coarse Aggregate, Water, Steel Reinforcement

Material	Main Function
Concrete	Resists compression
Steel	Resists tension
Concrete Cover	Protects steel from corrosion & fire
Stirrups	Shear resistance + holds longitudinal bars

Effective Depth (d) = Overall depth − Effective cover

2. Limit State Method (LSM)

Two main limit states: Collapse and Serviceability.

• Collapse → Flexure, Compression, Shear, Torsion
• Serviceability → Deflection, Cracking, Vibration

Design Load = Characteristic Load × Partial Safety Factor

3. Working Stress Method (WSM)

Traditional elastic method using permissible stresses and Factor of Safety.

Permissible Stress = Strength / Factor of Safety

4. Singly Reinforced Beam

Main flexural reinforcement only in tension zone.

Mu = T × z

5. Doubly Reinforced Beam

Reinforcement in both tension and compression zones. Used when depth is restricted or required moment > limiting moment of singly reinforced section.

RCC 50 MCQs (English) – SSC JE / JE Pattern

Instructions: Attempt all 50 questions. Click Submit Quiz to see score and explanations.
Questions based on recurring concepts from SSC JE, RRB JE and State JE exams (IS 456:2000).

Q1. As per IS 456:2000, the minimum grade of concrete for reinforced concrete is: (SSC JE)

A. M15 B. M20 C. M25 D. M30

As per IS 456:2000 Clause 6.1.2 – minimum grade for RCC is M20.

Q2. The modulus of elasticity of concrete as per IS 456:2000 is: (SSC JE)

A. 5000 √fck B. 5700 √fck C. 570 √fck D. 500 √fck

Ec = 5000 √fck (N/mm²) as per IS 456:2000.

Q3. For Fe 500 steel, the limiting xu/d for a singly reinforced section is: (SSC JE)

A. 0.53 B. 0.48 C. 0.46 D. 0.42

xu,max/d = 0.46 for Fe 500 (IS 456 Annex G / Table G).

Q4. Design bond stress for M20 concrete (plain bars in tension) as per IS 456 is: (SSC JE)

A. 1.0 N/mm² B. 1.2 N/mm² C. 1.4 N/mm² D. 1.5 N/mm²

Table 26.2.1.1 of IS 456 → τbd for M20 = 1.2 N/mm².

Q5. Minimum cement content for RCC under moderate exposure (20 mm aggregate) as per IS 456 is: (SSC JE)

A. 280 kg/m³ B. 300 kg/m³ C. 320 kg/m³ D. 350 kg/m³

Table 5 of IS 456:2000 – Moderate exposure, RCC → 300 kg/m³.

Q6. Partial safety factor for concrete in limit state design is: (SSC JE)

A. 1.15 B. 1.5 C. 1.0 D. 1.2

γm for concrete = 1.5; for steel = 1.15.

Q7. Maximum percentage of tension reinforcement in a beam as per IS 456 is: (SSC JE)

A. 2% B. 3% C. 4% D. 6%

Maximum tension reinforcement = 4% of gross sectional area (Cl. 26.5.1.1).

Q8. Nominal cover for moderate exposure as per IS 456 is: (SSC JE)

A. 20 mm B. 30 mm C. 45 mm D. 50 mm

Table 16 – Moderate exposure → 30 mm.

Q9. Development length Ld for a bar in tension is given by: (SSC JE)

A. (ϕ × σs)/(4 τbd) B. (ϕ × 0.87 fy)/(4 τbd) C. (ϕ × fy)/(4 τbd) D. (ϕ × 0.87 fy)/(2 τbd)

Ld = (ϕ × 0.87 fy)/(4 τbd) as per IS 456.

Q10. Doubly reinforced beams are mainly provided when: (SSC JE)

A. Depth is restricted B. Span is very large C. Load is very small D. Shear force is high

Used when available depth is restricted and required Mu > Mulim of singly reinforced section.

Q11. Characteristic strength of concrete is the strength below which not more than ___ % of results are expected to fall: (SSC JE)

A. 5% B. 10% C. 15% D. 20%

Definition of characteristic strength – not more than 5% results fall below it.

Q12. Target mean strength of concrete is given by: (SSC JE)

A. fck + 1.65σ B. fck + 1.5σ C. fck + σ D. fck + 2σ

fm = fck + 1.65σ (IS 456).

Q13. Maximum spacing of main reinforcement in a slab shall not exceed: (SSC JE)

A. 3d or 300 mm B. 2d or 300 mm C. 3d or 450 mm D. 2d or 450 mm

Main bars: lesser of 3d or 300 mm (Cl. 26.3.3).

Q14. Minimum percentage of tension reinforcement for Fe 415 in beams is approximately: (SSC JE)

A. 0.12% B. 0.15% C. 0.20% D. 0.85%

Ast,min = 0.85 bd/fy → for Fe 415 ≈ 0.205%.

Q15. Approximate lever arm for a balanced singly reinforced section is: (SSC JE)

A. 0.87d B. 0.90d C. 0.95d D. d

z ≈ 0.90d is commonly taken for balanced section.

Q16. In an under-reinforced section: (SSC JE)

A. Steel fails first B. Concrete fails first C. Both fail simultaneously D. Failure is sudden

Under-reinforced → steel yields first → ductile failure.

Q17. In an over-reinforced section: (SSC JE)

A. Steel fails first B. Concrete fails first C. Both fail together D. Large deflection occurs

Over-reinforced → concrete crushes first → brittle failure.

Q18. Minimum nominal cover for footing as per IS 456 is: (SSC JE)

A. 40 mm B. 50 mm C. 60 mm D. 75 mm

Minimum nominal cover for footing = 50 mm.

Q19. For Fe 415 steel, limiting xu/d is: (SSC JE)

A. 0.53 B. 0.48 C. 0.46 D. 0.42

xu,max/d = 0.48 for Fe 415.

Q20. Maximum shear stress in beams (even with shear reinforcement) shall not exceed: (SSC JE)

A. 0.63√fck B. 0.16√fck C. 0.36√fck D. 0.45√fck

τc,max = 0.63√fck (Cl. 40.2.3 of IS 456).

Q21. Minimum diameter of longitudinal bar in a column is: (SSC JE)

A. 8 mm B. 10 mm C. 12 mm D. 16 mm

Minimum diameter of longitudinal bars in column = 12 mm.

Q22. Minimum number of longitudinal bars in a rectangular column is: (SSC JE)

A. 3 B. 4 C. 6 D. 8

Minimum 4 bars in rectangular column.

Q23. Pitch of lateral ties in a column shall not exceed the least of: (SSC JE)

A. Least lateral dimension, 16 × dia of smallest longitudinal bar, 300 mm B. Least lateral dimension, 12 × dia, 300 mm C. 300 mm only D. 16 × dia only

Pitch ≤ least of: least lateral dimension, 16 × smallest longitudinal bar dia, 300 mm.

Q24. In limit state of collapse – flexure, the maximum compressive strain in concrete is taken as: (SSC JE)

A. 0.002 B. 0.0035 C. 0.003 D. 0.004

Maximum compressive strain in concrete = 0.0035.

Q25. Design stress-strain curve for concrete in limit state method is: (SSC JE)

A. Linear B. Parabolic up to 0.002 then constant C. Rectangular D. Triangular

Parabolic up to strain 0.002 and then constant till 0.0035.

Q26. The factor of safety for steel in working stress method is generally: (SSC JE)

A. 1.5 B. 1.78 C. 2.0 D. 3.0

For mild steel ≈ 1.78 (based on yield stress).

Q27. Modular ratio ‘m’ in working stress method is taken as: (SSC JE)

A. 280 / (3σcbc) B. 280 / σcbc C. 3σcbc / 280 D. Es / Ec

m = 280 / (3σcbc) as per IS 456 (WSM).

Q28. Minimum clear cover for beams as per IS 456 (mild exposure) is: (SSC JE)

A. 20 mm B. 25 mm C. 30 mm D. 40 mm

Minimum nominal cover for beam = 25 mm (mild exposure).

Q29. Side face reinforcement is provided in beams when depth exceeds: (SSC JE)

A. 450 mm B. 750 mm C. 900 mm D. 1000 mm

Side face reinforcement required when overall depth > 750 mm.

Q30. The maximum spacing of shear reinforcement (vertical stirrups) shall not exceed: (SSC JE)

A. 0.75d B. d C. 300 mm D. Both A and C (lesser of the two)

Maximum spacing of vertical stirrups = 0.75d or 300 mm, whichever is less.

Q31. In a balanced section (LSM): (SSC JE)

A. xu = xu,max B. xu < xu,max C. xu > xu,max D. Steel stress is less than 0.87fy

Balanced section → xu = xu,max.

Q32. The design compressive strength of concrete in limit state is taken as: (SSC JE)

A. 0.36 fck B. 0.45 fck C. 0.67 fck D. 0.87 fck

Average design stress in compression block = 0.36 fck.

Q33. The depth of rectangular stress block in limit state is taken as: (SSC JE)

A. 0.36 xu B. 0.42 xu C. 0.45 xu D. 0.48 xu

Centroid of stress block is at 0.42 xu from extreme compression fibre.

Q34. Minimum reinforcement in a slab (HYSD bars) is: (SSC JE)

A. 0.12% B. 0.15% C. 0.20% D. 0.25%

For HYSD bars / welded wire fabric → 0.12% of gross sectional area.

Q35. Lap length in tension for HYSD bars is generally taken as: (SSC JE)

A. Ld B. 1.3 Ld C. 2 Ld D. 40 ϕ

Lap length in tension = 1.3 Ld (or as per development length requirements).

Q36. The basic value of span to effective depth ratio for simply supported beam (span ≤ 10 m) is: (SSC JE)

A. 7 B. 20 C. 26 D. 35

Simply supported → 20; continuous → 26; cantilever → 7.

Q37. Effective length of a column fixed at both ends is: (SSC JE)

A. 0.65 L B. 0.80 L C. 1.0 L D. 1.2 L

Both ends fixed → recommended effective length = 0.65 L (IS 456 Table 28).

Q38. The minimum eccentricity for a column as per IS 456 is: (SSC JE)

A. L/300 + D/30 B. L/500 + D/30 C. L/300 + D/50 D. L/500 + D/50

emin = L/500 + D/30 but not less than 20 mm.

Q39. In working stress method, the permissible tensile stress in HYSD bars (Fe 415) is: (SSC JE)

A. 140 N/mm² B. 230 N/mm² C. 0.55 fy D. 0.87 fy

Half of the guaranteed yield stress subject to maximum of 230 N/mm² for HYSD bars.

Q40. The percentage of steel for a balanced singly reinforced section (Fe 415, M20) is approximately: (SSC JE)

A. 0.96% B. 1.2% C. 1.5% D. 2.0%

pt,lim ≈ 0.96% for Fe 415 & M20.

Q41. If T = 100 kN and lever arm z = 0.4 m, the moment of resistance is: (SSC JE pattern)

A. 25 kNm B. 40 kNm C. 100 kNm D. 250 kNm

M = T × z = 100 × 0.4 = 40 kNm.

Q42. If overall depth D = 500 mm and effective cover = 50 mm, effective depth is: (SSC JE pattern)

A. 450 mm B. 500 mm C. 550 mm D. 400 mm

d = D − effective cover = 500 − 50 = 450 mm.

Q43. Design load = Characteristic load × : (SSC JE)

A. Partial safety factor B. Factor of safety C. Load factor only D. 1.0

Design load = Characteristic load × Partial safety factor for load.

Q44. In limit state method, the design strength of steel in tension is taken as: (SSC JE)

A. 0.87 fy B. 0.67 fy C. fy D. 0.55 fy

Design stress in steel = 0.87 fy.

Q45. The ratio of the depth of neutral axis to the effective depth for a balanced section with Fe 250 is: (SSC JE)

A. 0.53 B. 0.48 C. 0.46 D. 0.42

xu,max/d = 0.53 for Fe 250.

Q46. Bond between steel and concrete is mainly due to: (SSC JE)

A. Adhesion, friction and mechanical interlock B. Only adhesion C. Only friction D. Chemical reaction

Bond is due to adhesion, friction and mechanical interlock (especially for deformed bars).

Q47. A doubly reinforced beam has reinforcement in: (SSC JE)

A. Tension zone only B. Compression zone only C. Both tension and compression zones D. Neutral axis only

Doubly reinforced = steel in both tension and compression zones.

Q48. Effective depth is measured from: (SSC JE)

A. Compression face to centroid of tension steel B. Top of beam to bottom of beam C. Neutral axis to tension steel D. Cover to cover

Effective depth d = distance from extreme compression fibre to centroid of tension reinforcement.

Q49. Limit state of collapse primarily ensures: (SSC JE)

A. Structural safety against failure B. Comfort under service loads C. Aesthetic appearance D. Economy only

Collapse limit state → strength and safety against failure.

Q50. For MP Sub Engineer / SSC JE Civil, the most important combination for RCC preparation is: (Exam oriented)

A. LSM + Beam design + IS 456 provisions B. Only painting & finishing C. Only architectural drawings D. Only landscaping

Core topics: Limit State Method, singly/doubly reinforced beams, and important codal provisions of IS 456:2000.

Your Score

Last Minute Revision

• Minimum grade for RCC → M20
• Ec = 5000 √fck
• xu,max/d → 0.53 (Fe250), 0.48 (Fe415), 0.46 (Fe500)
• γm (concrete) = 1.5 | γm (steel) = 1.15
• Design stress in steel = 0.87 fy
• Min cover (moderate) = 30 mm | Footing = 50 mm
• Ld = ϕ × 0.87 fy / (4 τbd)
• Max Ast in beam = 4%
• Under-reinforced → steel yields first (ductile)