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

0.446 fck and 0.87 fy respectively

0.4 fck and 0.67 fy respectively

0.446 fck and 0.87 fy respectively

0.67 fck and 0.67 fy respectively

0.446 fck and 0.67 fy respectively

A column of length ‘L’ is fixed at bottom end and hinged at the other end. This column is restrained from lateral displacement at 1/3rd height. The buckling load is given by

$\frac{{4{\pi ^2}EI}}{{{L^2}}}$

$\frac{{9{\pi ^2}EI}}{{\left( {4{L^2}} \right)}}$

$\frac{{4{\pi ^2}EI}}{{{L^2}}}$

$\frac{{4{\pi ^2}EI}}{{\left( {9{L^2}} \right)}}$

$\frac{{{\pi ^2}EI}}{{{L^2}}}$

A pin-ended column of length L, modulus of elasticity E and second moment ofthe cross-sectional area I is loaded centrically by a compressive load P. The critical buckling load (Pcr) is given by

${P_{cr}} = \frac{{EI}}{{{\pi ^2}{L^2}}}$

${P_{cr}} = \frac{{{\pi ^2}EI}}{{3{L^2}}}$

${P_{cr}} = \frac{{{\pi }EI}}{{{L^2}}}$

${P_{cr}} = \frac{{{\pi ^2}EI}}{{{L^2}}}$

Lateral ties in RCC columns are provided to resist

Buckling of longitudinal steel base

A vertical column has two moments of inertia (i.e. Ixx and Iyy). The column will tend to buckle in the direction of the:

perpendicular to the axis of load

Euler’s buckling load for a column with one end fixed and other end hinged condition is

$\frac{{4{\pi ^2}EI}}{{{L^2}}}$

$\frac{{{\pi ^2}EI}}{{{L^2}}}$

$\frac{{2{\pi ^2}EI}}{{{L^2}}}$

$\frac{{4{\pi ^2}EI}}{{{L^2}}}$

$\frac{{{\pi ^2}EI}}{{4{L^2}}}$

According to IS 456:2000, a pedestal is a compression member whose

Effective length does not exceed 4 times its least lateral dimension

Effective length does not exceed 2 times its least lateral dimension

Effective length does not exceed 3 times its least lateral dimension

Effective length does not exceed 4 times its least lateral dimension

Effective length does not exceed 5 times its least lateral dimension

113 + Mcqs in Design Columns in Strength Materials Page 2 McqOptions

51.	A bulkhead may also serve as a:
A.	beam
B.	slab
C.	pier
D.	footing
E.	wall
Answer» D. footing

Discussion

52.	A long column hinged at both the ends has certain critical Euler’s buckling load carrying capacity. If the same column be fixed at both the ends (in place of hinged ends), the load-carrying capacity then increases to
A.	4 times
B.	3 times
C.	2 times
D.	Nil
Answer» B. 3 times

Discussion

53.	A short RCC column is designed assuming maximum permissible axial compressive stresses in concrete and steel as:
A.	0.4 fck and 0.67 fy respectively
B.	0.446 fck and 0.87 fy respectively
C.	0.67 fck and 0.67 fy respectively
D.	0.446 fck and 0.67 fy respectively
Answer» B. 0.446 fck and 0.87 fy respectively

Discussion

54.	A RCC column is said to be short if length to diameter ratio is: _____.
A.	Less than 50
B.	Less than 30
C.	Less than 25
D.	Less than 8
Answer» E.

Discussion

55.	As per IS (Indian Standard) specifications, the minimum number of longitudinal bars provided in a column shall be _____ in rectangular columns and ______ in circular columns.
A.	6, 4
B.	4, 6
C.	4, 8
D.	6, 8
Answer» C. 4, 8

Discussion

56.	If the length of a pillar is 'L' whose one end is fixed and the other end is free, then its effective length will be taken as-
A.	2L
B.	L / 2
C.	L
D.	L / √2
Answer» B. L / 2

Discussion

57.	In order that no buckling occurs in a column, the equation of the neutral axis or the line of zero stress, where ‘e’ and ‘r’ are the eccentricities and radius of gyration of respective axis, is given by,
A.	1 + (ex/ry2) X + (ey/rx2) Y
B.	1 + (ex/rx2) X + (ey/ry2) Y
C.	(ex/ry2) X + (ey/rx2) Y
D.	(ex/rx2) X + (ey/ry2) Y
Answer» B. 1 + (ex/rx2) X + (ey/ry2) Y

Discussion

58.	A short column of the symmetric cross-section is subjected to an eccentric vertical compressive load P at an eccentricity ‘e’.To avoid tensile stress in the short column, the eccentricity ‘e’ should be
A.	$e \le \frac{h}{6}$
B.	$e \ge \frac{h}{6}$
C.	$e \le \frac{h}{3}$
D.	$e \ge \frac{h}{3}$
Answer» B. $e \ge \frac{h}{6}$

Discussion

59.	If one end of a hinged column is made fixed and other end free, how much is the critical load compared to the original value?
A.	Four times
B.	One-fourth
C.	One-half
D.	Twice
Answer» C. One-half

Discussion

60.	As per IS456-2000, what is the recommended length of column fixed at one end and hinged at other end?
A.	0.70L
B.	0.80L
C.	0.65L
D.	0.50L
Answer» C. 0.65L

Discussion

61.	If flexural rigidity of a column whose length is L and the loaded end is free, is EI, the critical load will be
A.	Pc = πEI/(4L2)
B.	Pc = π2EI/(4L2)
C.	Pc = πEI2/(4L2)
D.	None of these
Answer» C. Pc = πEI2/(4L2)

Discussion

62.	If Ix and IY are the moments of inertia of a section about X and Y axes, the polar moment of inertia of the section is
A.	(IX + IY)/2
B.	(IX - IY)/2
C.	IX + IY
D.	IX / IY
Answer» D. IX / IY

Discussion

63.	A column of length ‘L’ is fixed at bottom end and hinged at the other end. This column is restrained from lateral displacement at 1/3rd height. The buckling load is given by
A.	$\frac{{9{\pi ^2}EI}}{{\left( {4{L^2}} \right)}}$
B.	$\frac{{4{\pi ^2}EI}}{{{L^2}}}$
C.	$\frac{{4{\pi ^2}EI}}{{\left( {9{L^2}} \right)}}$
D.	$\frac{{{\pi ^2}EI}}{{{L^2}}}$
Answer» B. $\frac{{4{\pi ^2}EI}}{{{L^2}}}$

Discussion

64.	For a column of length L is fixed at both ends, corresponding Euler’s critical load is
A.	π3EI/L2
B.	2π2EI/L2
C.	3π2EI/L2
D.	4π2EI/L2
Answer» E.

Discussion

65.	If both ends of a 20 m long column are fixed, for Euler's load calculations, its effective length is taken to be:
A.	20 m
B.	40 m
C.	10 m
D.	20√2 m
Answer» D. 20√2 m

Discussion

66.	For the clamped- free column, the effective length is equal to:
A.	twice the actual length
B.	0.5 times the actual length
C.	the actual length
D.	0.7 times the actual length
Answer» B. 0.5 times the actual length

Discussion

67.	Four columns are identical in all parameters except end conditions. Arrange them in their ascending order of load carrying capacity.i. Both ends are hingedii. Both ends are fixediii. One end is fixed and the other end is freeiv. One end is fixed and the other end is hinged
A.	iii, i, iv, ii
B.	ii, iv, i, iii
C.	i, ii, iii, iv
D.	i, iv, iii, ii
Answer» B. ii, iv, i, iii

Discussion

68.	For a long slender column of uniform cross section, the ratio of critical buckling to load for the case with both ends clamped to the case with both ends hinged is
A.	1
B.	2
C.	4
D.	8
Answer» D. 8

Discussion

69.	A pin-ended column of length L, modulus of elasticity E and second moment ofthe cross-sectional area I is loaded centrically by a compressive load P. The critical buckling load (Pcr) is given by
A.	${P_{cr}} = \frac{{EI}}{{{\pi ^2}{L^2}}}$
B.	${P_{cr}} = \frac{{{\pi ^2}EI}}{{3{L^2}}}$
C.	${P_{cr}} = \frac{{{\pi }EI}}{{{L^2}}}$
D.	${P_{cr}} = \frac{{{\pi ^2}EI}}{{{L^2}}}$
Answer» E.

Discussion

70.	A column of size 450 mm × 600 mm has unsupported length of 3.0 m and is braced against side sway in both directions. According to IS 456: 2000, the minimum eccentricities (in mm) with respect to major and minor principal axes are:
A.	20.0 and 20.0
B.	26.0 and 21.0
C.	26.0 and 20.0
D.	21.0 and 15.0
Answer» C. 26.0 and 20.0

Discussion

71.	Euler's formula is applicable for which type of columns?
A.	Weak columns
B.	Long columns
C.	Short columns
D.	Strong columns
Answer» C. Short columns

Discussion

72.	A column cross-section 300 mm × 400 mm, 2250 mm long fixed at one end free at other end. The ratio of effective length to the least lateral dimension is:
A.	7.5
B.	15
C.	11.25
D.	9
Answer» C. 11.25

Discussion

73.	A column has a rectangular cross section of 10 × 20 mm and a length of 1 m. The slenderness ratio of the column is close to
A.	200
B.	346
C.	477
D.	1000
Answer» C. 477

Discussion

74.	If the length of a column subjected to compressive load is increased by three times its original length, the critical buckling load becomes
A.	1/3 of the original value
B.	3 times the original value
C.	1/9 of the original value
D.	1/27 of the original value
Answer» D. 1/27 of the original value

Discussion

75.	In reinforced concrete, pedestal is defined as a compression member, whose effective length does not exceed its least lateral dimension by
A.	3 times
B.	8 times
C.	12 times
D.	16 times
Answer» B. 8 times

Discussion

76.	A column with unsupported length of 3.5 m, cross-section 420 mm × 420 mm subjected to an axial load 1000 kN to be checked for minimum eccentricity is
A.	11 mm
B.	31 mm
C.	21 mm
D.	41 mm
Answer» D. 41 mm

Discussion

77.	For which type of column the buckling load will be maximum?
A.	One end clamped and other free
B.	Both ends clamped
C.	Both ends hinged
D.	One end hinged other is free
Answer» C. Both ends hinged

Discussion

78.	Euler’s formula for bucking of column does not hold good if slenderness ratio $\left( {\frac{{le}}{K}} \right)$ is ______ for mild steel column.
A.	Less than 80
B.	Greater than 90
C.	120 - 160
D.	90 - 120
Answer» B. Greater than 90

Discussion

79.	A 1.5 m long column has a circular cross-section of 50 mm diameter. Consider Rankine’s formula with values of fc = 560 N/mm2, $\alpha = \frac{1}{{1600}}$ for pinned ends and factor of safety of 3. If one end of the column is fixed and the other end is free, the safe load will be
A.	9948 N
B.	9906 N
C.	9864 N
D.	9822 N
Answer» C. 9864 N

Discussion

80.	Figure below shows a mass of 300 kg being pushed using a cylindrical rod made of a material having E = 22 MPa and of 2 m length and 0.1 m in diameter. In order to avoid the failure of the rod due to elastic instability, the maximum value of the co-efficient of Coulomb friction permissible between the mass and the floor is
A.	0.22
B.	0.36
C.	0.65
D.	0.75
Answer» B. 0.36

Discussion

81.	Lateral ties in RCC columns are provided to resist
A.	Bending moment
B.	Shear
C.	Buckling of longitudinal steel base
D.	Both Bending moment and shear
Answer» D. Both Bending moment and shear

Discussion

82.	Maximum load carrying capacity is of a column having
A.	one end fixed other end hinged
B.	both ends hinged
C.	both ends fixed
D.	one end fixed other end free
Answer» D. one end fixed other end free

Discussion

83.	A structural member subjected to an axial compressive force is called as
A.	Beam
B.	Column
C.	Frame
D.	Strut
Answer» E.

Discussion

84.	A vertical column has two moments of inertia (i.e. Ixx and Iyy). The column will tend to buckle in the direction of the:
A.	axis of load
B.	perpendicular to the axis of load
C.	maximum moment of inertia
D.	minimum moment of inertia
Answer» E.

Discussion

85.	If one end of a hinged column is made fixed and the other free, how much is the critical load compared to the original value?
A.	One-fourth
B.	One-half
C.	Twice
D.	Four times
Answer» B. One-half

Discussion

86.	A compression member has one end hinged and other end rigidly fixed against rotation and sway. Its Euler’s buckling load is 120 kN. What will be its buckling load if its both end are fixed against sway and rotation?
A.	60 kN
B.	120 kN
C.	240 kN
D.	120 √2 kN
Answer» D. 120 √2 kN

Discussion

87.	In Rankine's formula, the material constant for mild steel is:
A.	1/9000
B.	1/5000
C.	1/1600
D.	1/7500
Answer» E.

Discussion

88.	For normal M20 reinforced concrete, the time of removing the vertical form work for columns as per IS 456 is
A.	1 day
B.	3 days
C.	14 days
D.	28 days
Answer» B. 3 days

Discussion

89.	A column of height h with a rectangular cross-section of size a × 2a has a buckling load of P. If the cross-section is changed to 0.5a × 3a and its height changed to 1.5h, the buckling load of the redesigned column will be
A.	P/12
B.	P/4
C.	P/2
D.	3P/4
Answer» B. P/4

Discussion

90.	If the crushing load of a column is 2000 kN and the Euler load is 2000 kN, then the Rankine load is
A.	12000 kN
B.	1200 kN
C.	3000 kN
D.	2000 kN
E.	1000 kN
Answer» F.

Discussion

91.	A structural member subjected to compression has both translation and rotation restrained at one end, while only translation is restrained at the other end. As per IS 456:2000, the effective length factor recommended for design is
A.	0.50
B.	0.65
C.	0.70
D.	0.80
E.	1
Answer» E. 1

Discussion

92.	Euler’s buckling load for a column with one end fixed and other end hinged condition is
A.	$\frac{{{\pi ^2}EI}}{{{L^2}}}$
B.	$\frac{{2{\pi ^2}EI}}{{{L^2}}}$
C.	$\frac{{4{\pi ^2}EI}}{{{L^2}}}$
D.	$\frac{{{\pi ^2}EI}}{{4{L^2}}}$
Answer» C. $\frac{{4{\pi ^2}EI}}{{{L^2}}}$

Discussion

93.	Determine the minimum and maximum longitudinal reinforcement for a square column of size 300 mm × 300 mm having a clear cover of 25 mm.
A.	500 mm2 and 3750 mm2
B.	500 mm2 and 5400 mm2
C.	720 mm2 and 3750 mm2
D.	720 mm2 and 5400 mm2
Answer» E.

Discussion

94.	As per IS456-2000, a longitudinal steel reinforcement for column shall not be less than _______ of the gross cross-sectional area of the column.
A.	0.8%
B.	0.2%
C.	0.45%
D.	0.15%
Answer» B. 0.2%

Discussion

95.	A 4 m long solid round bar is used as a column having one end fixed and the other end free. If Euler’s critical load on this column is found as 10 kN and E = 210 GPa for the material of the bar, the diameter of the bar is
A.	50 mm
B.	40 mm
C.	60 mm
D.	45 mm
Answer» B. 40 mm

Discussion

96.	A circular rod of length l = 2 m is subjected to a compressive load P, as shown in the figure. The bending (flexural) rigidity of the rod is 2000 Nm2 . If both ends are pinned, then the critical load Pcr in N (rounded to the nearest integer) at which the rod buckles elastically is
A.	4935
B.	2000
C.	5167
D.	1238
Answer» B. 2000

Discussion

97.	For long column the equivalent length for both end fixed is
A.	Le = L
B.	$L_e ~=~\frac{L}{\sqrt2}$
C.	$L_e ~=~\frac{L}{2}$
D.	Le = 2L
Answer» D. Le = 2L

Discussion

98.	According to IS 456:2000, a pedestal is a compression member whose
A.	Effective length does not exceed 2 times its least lateral dimension
B.	Effective length does not exceed 3 times its least lateral dimension
C.	Effective length does not exceed 4 times its least lateral dimension
D.	Effective length does not exceed 5 times its least lateral dimension
Answer» C. Effective length does not exceed 4 times its least lateral dimension

Discussion

99.	A_SYSTEM_IN_WHICH_WATER_IS_SUPPLIED_ONLY_FOR_FIXED_FEW_HOURS,_SUCH_SYSTEM_IS_CALLED_____?$
A.	Closed
B.	Intermittent
C.	Combined
D.	Lift
Answer» C. Combined

Discussion

100.	WHICH_OF_THE_FOLLOWING_RESERVOIRS_IS_ALSO_KNOWN_AS____________?$
A.	Ground service reservoirs
B.	Elevated reservoirs
C.	Over head reservoirs
D.	Storey reservoirs
Answer» B. Elevated reservoirs

Discussion

58.	A short column of the symmetric cross-section is subjected to an eccentric vertical compressive load P at an eccentricity ‘e’.To avoid tensile stress in the short column, the eccentricity ‘e’ should be
A.	\(e \le \frac{h}{6}\)
B.	\(e \ge \frac{h}{6}\)
C.	\(e \le \frac{h}{3}\)
D.	\(e \ge \frac{h}{3}\)
Answer» B. \(e \ge \frac{h}{6}\)

63.	A column of length ‘L’ is fixed at bottom end and hinged at the other end. This column is restrained from lateral displacement at 1/3rd height. The buckling load is given by
A.	\(\frac{{9{\pi ^2}EI}}{{\left( {4{L^2}} \right)}}\)
B.	\(\frac{{4{\pi ^2}EI}}{{{L^2}}}\)
C.	\(\frac{{4{\pi ^2}EI}}{{\left( {9{L^2}} \right)}}\)
D.	\(\frac{{{\pi ^2}EI}}{{{L^2}}}\)
Answer» B. \(\frac{{4{\pi ^2}EI}}{{{L^2}}}\)

69.	A pin-ended column of length L, modulus of elasticity E and second moment ofthe cross-sectional area I is loaded centrically by a compressive load P. The critical buckling load (Pcr) is given by
A.	\({P_{cr}} = \frac{{EI}}{{{\pi ^2}{L^2}}}\)
B.	\({P_{cr}} = \frac{{{\pi ^2}EI}}{{3{L^2}}}\)
C.	\({P_{cr}} = \frac{{{\pi }EI}}{{{L^2}}}\)
D.	\({P_{cr}} = \frac{{{\pi ^2}EI}}{{{L^2}}}\)
Answer» E.

92.	Euler’s buckling load for a column with one end fixed and other end hinged condition is
A.	\(\frac{{{\pi ^2}EI}}{{{L^2}}}\)
B.	\(\frac{{2{\pi ^2}EI}}{{{L^2}}}\)
C.	\(\frac{{4{\pi ^2}EI}}{{{L^2}}}\)
D.	\(\frac{{{\pi ^2}EI}}{{4{L^2}}}\)
Answer» C. \(\frac{{4{\pi ^2}EI}}{{{L^2}}}\)

97.	For long column the equivalent length for both end fixed is
A.	Le = L
B.	\(L_e ~=~\frac{L}{\sqrt2}\)
C.	\(L_e ~=~\frac{L}{2}\)
D.	Le = 2L
Answer» D. Le = 2L

Explore topic-wise MCQs in Strength Materials.

A bulkhead may also serve as a:

A long column hinged at both the ends has certain critical Euler’s buckling load carrying capacity. If the same column be fixed at both the ends (in place of hinged ends), the load-carrying capacity then increases to

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

A RCC column is said to be short if length to diameter ratio is: _____.

As per IS (Indian Standard) specifications, the minimum number of longitudinal bars provided in a column shall be _____ in rectangular columns and ______ in circular columns.

If the length of a pillar is 'L' whose one end is fixed and the other end is free, then its effective length will be taken as-

In order that no buckling occurs in a column, the equation of the neutral axis or the line of zero stress, where ‘e’ and ‘r’ are the eccentricities and radius of gyration of respective axis, is given by,

A short column of the symmetric cross-section is subjected to an eccentric vertical compressive load P at an eccentricity ‘e’.To avoid tensile stress in the short column, the eccentricity ‘e’ should be

If one end of a hinged column is made fixed and other end free, how much is the critical load compared to the original value?

As per IS456-2000, what is the recommended length of column fixed at one end and hinged at other end?

If flexural rigidity of a column whose length is L and the loaded end is free, is EI, the critical load will be

If Ix and IY are the moments of inertia of a section about X and Y axes, the polar moment of inertia of the section is

A column of length ‘L’ is fixed at bottom end and hinged at the other end. This column is restrained from lateral displacement at 1/3rd height. The buckling load is given by

For a column of length L is fixed at both ends, corresponding Euler’s critical load is

If both ends of a 20 m long column are fixed, for Euler's load calculations, its effective length is taken to be:

For the clamped- free column, the effective length is equal to:

Four columns are identical in all parameters except end conditions. Arrange them in their ascending order of load carrying capacity.i. Both ends are hingedii. Both ends are fixediii. One end is fixed and the other end is freeiv. One end is fixed and the other end is hinged

For a long slender column of uniform cross section, the ratio of critical buckling to load for the case with both ends clamped to the case with both ends hinged is

A pin-ended column of length L, modulus of elasticity E and second moment ofthe cross-sectional area I is loaded centrically by a compressive load P. The critical buckling load (Pcr) is given by

A column of size 450 mm × 600 mm has unsupported length of 3.0 m and is braced against side sway in both directions. According to IS 456: 2000, the minimum eccentricities (in mm) with respect to major and minor principal axes are:

Euler's formula is applicable for which type of columns?

A column cross-section 300 mm × 400 mm, 2250 mm long fixed at one end free at other end. The ratio of effective length to the least lateral dimension is:

A column has a rectangular cross section of 10 × 20 mm and a length of 1 m. The slenderness ratio of the column is close to

If the length of a column subjected to compressive load is increased by three times its original length, the critical buckling load becomes

In reinforced concrete, pedestal is defined as a compression member, whose effective length does not exceed its least lateral dimension by

A column with unsupported length of 3.5 m, cross-section 420 mm × 420 mm subjected to an axial load 1000 kN to be checked for minimum eccentricity is

For which type of column the buckling load will be maximum?

Euler’s formula for bucking of column does not hold good if slenderness ratio \(\left( {\frac{{le}}{K}} \right)\) is ______ for mild steel column.

A 1.5 m long column has a circular cross-section of 50 mm diameter. Consider Rankine’s formula with values of fc = 560 N/mm2, \(\alpha = \frac{1}{{1600}}\) for pinned ends and factor of safety of 3. If one end of the column is fixed and the other end is free, the safe load will be

Lateral ties in RCC columns are provided to resist

Maximum load carrying capacity is of a column having

A structural member subjected to an axial compressive force is called as

A vertical column has two moments of inertia (i.e. Ixx and Iyy). The column will tend to buckle in the direction of the:

If one end of a hinged column is made fixed and the other free, how much is the critical load compared to the original value?

A compression member has one end hinged and other end rigidly fixed against rotation and sway. Its Euler’s buckling load is 120 kN. What will be its buckling load if its both end are fixed against sway and rotation?

In Rankine's formula, the material constant for mild steel is:

For normal M20 reinforced concrete, the time of removing the vertical form work for columns as per IS 456 is

A column of height h with a rectangular cross-section of size a × 2a has a buckling load of P. If the cross-section is changed to 0.5a × 3a and its height changed to 1.5h, the buckling load of the redesigned column will be

If the crushing load of a column is 2000 kN and the Euler load is 2000 kN, then the Rankine load is

A structural member subjected to compression has both translation and rotation restrained at one end, while only translation is restrained at the other end. As per IS 456:2000, the effective length factor recommended for design is

Euler’s buckling load for a column with one end fixed and other end hinged condition is

Determine the minimum and maximum longitudinal reinforcement for a square column of size 300 mm × 300 mm having a clear cover of 25 mm.

As per IS456-2000, a longitudinal steel reinforcement for column shall not be less than _______ of the gross cross-sectional area of the column.

A 4 m long solid round bar is used as a column having one end fixed and the other end free. If Euler’s critical load on this column is found as 10 kN and E = 210 GPa for the material of the bar, the diameter of the bar is

A circular rod of length l = 2 m is subjected to a compressive load P, as shown in the figure. The bending (flexural) rigidity of the rod is 2000 Nm2 . If both ends are pinned, then the critical load Pcr in N (rounded to the nearest integer) at which the rod buckles elastically is

For long column the equivalent length for both end fixed is

According to IS 456:2000, a pedestal is a compression member whose

A_SYSTEM_IN_WHICH_WATER_IS_SUPPLIED_ONLY_FOR_FIXED_FEW_HOURS,_SUCH_SYSTEM_IS_CALLED_____?$

WHICH_OF_THE_FOLLOWING_RESERVOIRS_IS_ALSO_KNOWN_AS____________?$

As per IS (Indian Standard) specifications, the minimum number of longitudinal bars provided in a column shall be _ in rectangular columns and __ in circular columns.