Columns MCQ Quiz - Objective Question with Answer for Columns - Download Free PDF

Last updated on Jul 10, 2025

Latest Columns MCQ Objective Questions

Columns Question 1:

Which of the following is a key difference between short columns and long columns?

  1. Long columns have a higher slenderness ratio compared to short columns.
  2. Short columns fail due to buckling, while long columns fail due to crushing.
  3. Long columns experience pure axial compression, while short columns experience lateral deflection.
  4. Short columns are only used in steel structures, while long columns are used in concrete structures.

Answer (Detailed Solution Below)

Option 1 : Long columns have a higher slenderness ratio compared to short columns.

Columns Question 1 Detailed Solution

Explanation:

Slenderness Ratio:

  • Slenderness Ratio (λ) = Effective Length (L) / Radius of Gyration (r)

  • It is used to classify columns:

    • Short Column: Low slenderness ratio (generally λ < 12)

    • Long Column: High slenderness ratio (λ > 12)

Failure Modes:

  • Short columns primarily fail due to crushing (material failure).

  • Long columns fail due to buckling (instability under axial load).

Columns Question 2:

According to IS 456:2000, for a column effectively held in position at one end but not restrained against rotation, and at the other end restrained against rotation but not held in position, the theoretical value of effective length is: 

  1. equal to the unsupported length
  2. 2.0 times the unsupported length
  3. 0.5 times the unsupported length
  4. 1.5 times the unsupported length

Answer (Detailed Solution Below)

Option 2 : 2.0 times the unsupported length

Columns Question 2 Detailed Solution

Concept:

The effective length of compression members is given by

Symbol

Effective length

(Theoretical)

Effective length

(Recommended)

 

F1 N.M. N.J. 26.09.2019 D 10

Top: (Fixed)

  • Restrained against rotation
  • Held in position 

Bottom: (Fixed)

  • Restrained against rotation
  • Held in position 

0.50 l

0.65 l

 

F1 N.M. N.J. 26.09.2019 D 11

Top: (Hinged)

  • Not Restrained against rotation
  • Held in position

Bottom: (Fixed)

  • Restrained against rotation
  • Held in position 

0.70 l

0.80 l

 

F1 N.M. N.J. 26.09.2019 D 12

Top: (Hinged)

  • Not Restrained against rotation
  • Held in position

Bottom: (Hinged)

  • Not Restrained against rotation
  • Held in position

1.00 l

1.00 l

 

F1 N.M. N.J. 26.09.2019 D 13

Top: (Guided roller)

  • Restrained against rotation
  • Not held in position

Bottom: (Fixed)

  • Restrained against rotation
  • Held in position 

1.00 l

1.20 l

 

F1 N.M. N.J. 26.09.2019 D 14

Top: (Guided roller)

  • Partially Restrained against rotation
  • Not held in position

Bottom: (Fixed)

  • Restrained against rotation
  • Held in position 

 

-

1.50 l

 

F1 N.M. N.J. 26.09.2019 D 15

Top: (Guided roller)

  • Partially Restrained against rotation
  • Not held in position

Bottom: (Hinged)

  • Not Restrained against rotation
  • Held in position

2.00 l

2.00 l

 

F1 N.M. N.J. 26.09.2019 D 16

Top (free)

  • Not restrained against rotation
  • Not held in position

Bottom: (Fixed)

  • Restrained against rotation
  • Held in position 

2.00 l

2.00 l

Columns Question 3:

According to IS 456:2000, a column is classified as a short column if the slenderness factor about both the major and minor principal axes is less than:

  1. 22
  2. 12
  3. 34
  4. 40

Answer (Detailed Solution Below)

Option 2 : 12

Columns Question 3 Detailed Solution

Explanation:
As per IS 456:2000, clause 25.1.1
A column or strut is a compression member in which the effective length of the column or strut exceeds three times the least lateral dimension.

i.e. Leff > (3x Least Lateral Dimension)

A compression member may be considered as short when both the slenderness ratio Lex/D and Ley/b are less than 12.

where
Lex = effective length with respect to the major axis
D = depth with respect to the major axis
Ley = effective length with respect to the minor axis
b = width of the member

Columns Question 4:

According to IS 456:2000, the maximum compressive strain in concrete under axial loading at the limit state of collapse is specified as ______.

  1. 0.002
  2. 0.0015
  3. 0.0025
  4. 0.003

Answer (Detailed Solution Below)

Option 1 : 0.002

Columns Question 4 Detailed Solution

Explanation:

  • According to IS 456:2000, the maximum compressive strain in concrete under axial loading at the limit state of collapse is taken as 0.002.
  • This is a standard value used to define the ultimate strain in concrete at the failure point under axial loads.

 Additional Information

  • Strain Compatibility: The value of 0.002 is used in conjunction with the stress-strain curve for concrete, particularly in the design of reinforced concrete beams and columns. This strain value helps in determining the ultimate strength of concrete elements, ensuring that structures can carry the required loads safely.

  • Safety Considerations: By using this limit state of collapse strain, the design ensures that the concrete remains within the elastic limit for most of the service life, only reaching failure (at 0.002 strain) under extreme loading conditions.

Columns Question 5:

A compression member may be considered as short when both the slenderness ratio l/D and l/b are less than:

  1. 8
  2. 10
  3. 15
  4. 12
  5. 16

Answer (Detailed Solution Below)

Option 4 : 12

Columns Question 5 Detailed Solution

Explanation:

As per IS 456:2000, clause 25.1.1

A column or strut is a compression member in which the effective length of the column or strut exceeds three times the least lateral dimension.

\(i.e. \;L_{eff}>(3\times Least \;Lateral\;Dimension)\)

A compression member may be considered as short when both the slenderness ratio \(L_{ex}\over D\) and \(L_{ey}\over b\) are less than 12.

where

Lex = effective length with respect to the major axis

D = depth with respect to the major axis

Ley = effective length with respect to the minor axis

b = width of the member

Top Columns MCQ Objective Questions

The minimum eccentricity to be considered for an axially loaded RCC column of size 400 mm × 400 mm with unsupported length of 5 m is:

  1. 15.6 mm
  2. 20.5 mm
  3. 23.3 mm
  4. 30.6 mm

Answer (Detailed Solution Below)

Option 3 : 23.3 mm

Columns Question 6 Detailed Solution

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Concept:

As per IS 456: 2000, clause 25.4,

Minimum Eccentricity

All columns shall be designed for minimum eccentricity, equal to the addition of the unsupported length of column divided by 500 and lateral dimensions divided by 30, subject to a minimum of 20 mm.

Where biaxial bending is considered, it is sufficient to ensure that eccentricity exceeds the minimum about one axis at a time.

Calculation:

Unsupported length = 5000 mm

Size of the column = 400 mm

Minimum eccentricity = \(\frac{L}{{500}} + \frac{B}{{30}} \)

\(e_{min}= \;\frac{{5000}}{{500}} + \frac{{400}}{{30}} = 23.33\;mm\;\)

But, in no case, the minimum eccentricity should be less than 20 mm.

According to IS 456 : 2000, the minimum and maximum percentage of longitudinal reinforcement in a column (expressed as percentage of gross cross-sectional area of the column), are respectively:

  1. 0.4 and 4
  2. 0.5 and 8
  3. 0.8 and 6
  4. 1 and 10

Answer (Detailed Solution Below)

Option 3 : 0.8 and 6

Columns Question 7 Detailed Solution

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Explanation:

Longitudinal Reinforcement:

(i) CI. 26.5.3 of IS 456:2000, specifies that the total area of longitudinal bars in a column section must NOT be less than 0.8% of the gross column area. This limit on minimum reinforcement is imposed because of the following reasons:

  • In order to ensure that a minimum flexural resistance of the column exists due to unexpected eccentricities in the column loading.
  • In compression members, creep under sustained loading is very predominant, especially at low percentages of steel. Thus, the resulting creep stress (due to creep strain) tries to yield the bars. 

(ii) Maximum Reinforcement: The maximum area of cross-section of longitudinal bars must NOT exceed 6% of gross column area. However, in practice, a maximum of 4% is recommended.


Additional Information

Diameter and Number of bar:

(i) The diameter of longitudinal bars in column NOT be less than 12 mm. These bars must NOT be spaced more than 300 mm apart on the column perimeter.

(ii) For rectangular columns. a minimum of 4 bars is provided.

(iii) For Circular columns, a minimum of 6 bars be provided.

Cover = 40 mm or bar diameter

A short RCC column is designed assuming maximum permissible axial compressive stresses in concrete and steel as:

  1. 0.4 fck and 0.67 fy respectively
  2. 0.446 fck and 0.87 fy respectively
  3. 0.67 fck and 0.67 fy respectively
  4. 0.446 fck and 0.67 fy respectively

Answer (Detailed Solution Below)

Option 1 : 0.4 fck and 0.67 fy respectively

Columns Question 8 Detailed Solution

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The permissible design stresses for an RCC Column under different conditions are given below:

1. If minimum eccentricity is considered to be Zero i.e. emin = 0

a. Permissible axial compressive stress in concrete = 0.45 fck

b. Permissible axial compressive stress in steel = 0.75 f

2. If minimum eccentricity effect is considered: 

a. Permissible axial compressive stress in concrete = 0.4 fck

b. Permissible axial compressive stress in steel = 0.67 f

Note:

In RCC beam subjected to bending, shear and torsion, the permissible values in steel and concrete are:

a. Design strength of concrete in flexure = 0.45 fck

b. Design strength of Steel in tension = 0.87fy

A reinforced concrete column of size 400 mm × 400 mm is having the diameter of longitudinal bar as 20 mm. The pitch of lateral ties in such a case should be:

  1. 320 mm
  2. 400 mm
  3. 300 mm
  4. 250 mm

Answer (Detailed Solution Below)

Option 3 : 300 mm

Columns Question 9 Detailed Solution

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Concept:

As per IS 456:2000, clause 26.5.3.2 (c), 

Pitch:

The pitch of transverse reinforcement shall be not more than the least of the following distances:

  1. the least lateral dimension of the compression members
  2. 16 times the smallest diameter of the longitudinal reinforcement bar to be tied (i.e. 16 φmin)
  3. 300 mm

 

The diameter of the Lateral Ties: 

The diameter of the lateral ties shall be not less than one-fourth of the diameter of the largest longitudinal bar and in no case less than 6 mm.

Calculations:

The pitch of transverse reinforcement shall be

  1. The lest lateral dimension = 400 mm
  2. 16 × 20 mm = 320 mm
  3. 300 mm

whichever is smaller

Hence, the pitch of lateral ties shall be kept as 300 mm.

The maximum spacing of spiral tie is ____ mm.

  1. 75
  2. 200
  3. 300
  4. 450

Answer (Detailed Solution Below)

Option 1 : 75

Columns Question 10 Detailed Solution

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Explanation:

As per IS 456:2000, clause 39.4,

Compression Member with Helical Reinforcement

\(Pitch < \begin{Bmatrix} \frac{Core diameter}{6}\\75 mm\end{Bmatrix} \)

In the given question, the core diameter is not given, so we have to take 75 mm only

Important Points

The strength of compression members with helical reinforcement shall be taken as 1.05 times the strength of similar members with lateral ties provided the condition

 \({Volume\; of\; helical\; reinforcement\over Volume\; of\; the\; core}\nless 0.36\left( {\frac{{{A_g}}}{{{A_c}}} - 1} \right)\frac{{{f_{ck}}}}{{{f_y}}}\;\)should be satisfied.

where

Ag = gross area of the section

Ac = area of the core of the helically reinforced column measured to the outside diameter of the helix

fck = characteristic compressive strength of the concrete

fy = characteristic strength of the helical reinforcement but not exceeding 415 N/mm2

Hence, the load-carrying capacity of the column with helical reinforcement is increased by 5% due to increased strength as a result of better confinement.

According to IS456-2000, a column or strut is a compression member whose effective length exceeds:

  1. 2 times the least lateral dimension
  2. 3 times the least lateral dimension
  3. 5 times the least lateral dimension
  4. 4 times the least lateral dimension

Answer (Detailed Solution Below)

Option 2 : 3 times the least lateral dimension

Columns Question 11 Detailed Solution

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Explanation:

As per IS 456:2000, clause 25.1.1,

A column or struts is a compression member in which the effective length of column or struts exceeds three times the least lateral dimension.

i.e. Leff > (3 × Least Lateral Dimension) 

A compression member may be considered as short when both the slenderness ratio \(L_{ex}\over D\) and \(L_{ey}\over b\) are less than 12.

where

Lex = effective length with respect to the major axis

D = depth with respect to the major axis

Ley = effective length with respect to the minor axis

b = width of the member

The length of column is 3.5 m and its size is 350 × 350 mm. For this column, the minimum eccentricity is ______

  1. 19 mm
  2. 18 mm
  3. 17 mm
  4. 20 mm

Answer (Detailed Solution Below)

Option 4 : 20 mm

Columns Question 12 Detailed Solution

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Concept:

As per IS 456: 2000, clause 25.4,

Minimum Eccentricity

All columns shall be designed for minimum eccentricity, equal to the addition of the unsupported length of column divided by 500 and lateral dimensions divided by 30, subject to a minimum of 20 mm.

Where biaxial bending is considered, it is sufficient to ensure that eccentricity exceeds the minimum about one axis at a time.

Calculation:

Given,

Unsupported length = 3500 mm

Size of the column = 350 mm

Minimum eccentricity = \(\frac{L}{{500}} + \frac{B}{{30}} \)

\(e_{min}= \;\frac{{3500}}{{500}} + \frac{{350}}{{30}} = 18.667\;mm\;\)

But, in no case, the minimum eccentricity should be less than 20 mm.

as e min < 20 mm.

The Minimum eccentricity = 20 mm

Reduction co- efficient of a reinforced concrete column with an effective length of 4.5 m and size 200 × 250 mm is ______.

  1. 0.78
  2. 0.68
  3. 0.70
  4. 0.60

Answer (Detailed Solution Below)

Option 1 : 0.78

Columns Question 13 Detailed Solution

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Concept:

In the design of long columns considering the factor of buckling, lower value of working stresses in steel and concrete is adopted, by multiplying the general working stresses by the reduction coefficient.

 \(C_r= 1.25-\frac{{{l_{eff}}}}{{48D}} \ or\ 1.25-\frac{{{l_{eff}}}}{{48B}}\) 

where,

Cr = Reduction coefficient

B and D = Least lateral dimension of the column

leff = Effective Length of the column

Calculation:

Given,

leff = 4.5 m

B = 200 mm

D = 250 mm

Cr = 1.25 - 4500/(48 x 200) = 0.78  or 1.25 - 4500/(48 x 250) = 0.875

Lesser value adopted, so Cr = 0.78

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  • If Effective Length / Least Lateral Dimension > 12, Long column otherwise short.

As per IS 456 ∶ 2000, determine the minimum eccentricity of the axial load, for an axially loaded column of size 300 mm × 300 mm, having an effective length of 3.5 m?

  1. 25 mm
  2. 20 mm
  3. 17 mm
  4. 10 mm

Answer (Detailed Solution Below)

Option 2 : 20 mm

Columns Question 14 Detailed Solution

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Concepts:

As per IS 456: 2000, clause 25.4, all columns shall be designed for minimum eccentricity, equal to the summation of the unsupported length of column divided by 500 and lateral dimensions divided by 30, subject to a minimum of 20 mm. i.e.

 The eccentricity is the maximum of the following:

→ \(e = \frac{L}{500} + \frac{B}{30}\)

→  e = 20 mm
Where L is the effective length of the column and B is the lateral dimension.

Further, where biaxial bending is considered, it is sufficient to ensure that eccentricity exceeds the minimum about one axis at a time.

Calculation:

Given:

Effective Length of Column, L = 3.5 m

Lateral Dimension, B = 300 mm

Minimum eccentricity, e is calculated as:

\(e = \frac{3500}{500} + \frac{300}{30}\)

e = 17 mm < emin = 20 mm

Therefore, the minimum eccentricity for an axially loaded column should be 20 mm.

The minimum area of longitudinal reinforcement in a RCC column of size 200 mm x 400 mm, shall not be less than______.

  1. 800 mm2
  2. 640 mm2
  3. 350 mm2
  4. 1200 mm2

Answer (Detailed Solution Below)

Option 2 : 640 mm2

Columns Question 15 Detailed Solution

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Concept: 

As per IS 456: 2000, clause 26.5.3.1,

Longitudinal reinforcement in a column:

Percentage of steel:

  • The cross-sectional area of longitudinal reinforcement shall be not less than 0.8 percent nor more than 6 percent of the gross cross-sectional area of the column.

Minimum diameter of longitudinal reinforcement bars:

  • The main longitudinal reinforcement bars used in the column shall not be less than 12 mm in diameter.

The minimum number of longitudinal bars:

The minimum number of the longitudinal bar provided in the column shall be

  • four in rectangular columns
  • six in circular columns

Helical reinforcement:

  • A reinforced concrete column having helical reinforcement shall have at least six-bar of longitudinal reinforcements within the helical reinforcement.

Spacing:

  • The spacing of longitudinal bars measured along the periphery of the column shall not exceed 300 mm.

Calculation:

Given data,

Size of RCC column = 200 mm x 400 mm

Hence, The minimum area of longitudinal reinforcement in an RCC column is 

= 0.008 × 200 × 400 = 640 mm2

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