The most economical section for a column, is
Rectangular
Solid round
Flat strip
Tubular section
Correct Answer :
D. Tubular section
Related Questions
Diameter of a rivet hole is made larger than the diameter of the rivet by
1.0 mm for rivet diameter upto 12 mm
1.5 mm for rivet diameter exceeding 25 mm
2.0 mm for rivet diameter over 25 mm
None of these
Pick up the correct statement from the following:
When the gauge distance is larger than the pitch, the failure of the section may occur in a zig-zag line
When the gauge distance is smaller than the pitch, the failure of the section may occur in a straight right angle section through the centre of rivet holes
When the gauge distance and pitch are both equal, the failure to the section becomes more likely as the diameter of the holes increases
All the above
The maximum tensile and compressive bending stress in extreme fibres of rolled I-sections and channels on the effective section, is
1500 kg/cm2
1420 kg/cm2
1650 kg/cm2
2285 kg/cm2
For simply supported beams, the maximum permitted deflection, is
1/325 of the span
1/350 of the span
1/375 of the span
1/400 of the span
A 20 mm dia steel bar which is subjected to an axial tension of 2300 kg/cm2 produces a strain of 0.004 cm. If Young's modulus of steel is 2.1 × kg/cm2, the bar is
In the elastic range
In the plastic range
At yield point
None of these
The slenderness ratio of a column is zero when its length
Is zero
Is equal to its radius of gyration
Is supported on all sides throughout its length
Is between the points of zero moments
As compared to field rivets, the shop rivets are
Stronger
Weaker
Equally strong
Any of the above
Assuming the values of maximum deviation ΔP and ΔE to be 25% of the computed value of P and E respectively, the minimum value of the factor of safety is
1.00
0.67
1.67
2.67
For a steel member of slenderness ratio 350, the allowable stress is 76 kg/cm2 if it is
HTW grade of thickness exceeding 32 mm
HT grade of thickness exceeding 45 mm
HT grade of thickness not exceeding 45 mm
All the above
The effect of racking forces is considered in the design of (i) Lateral braces (ii) Chord members The correct answer is
Only (i)
Only (ii)
Both (i) and (ii)
None of the above
Select the correct statement
Material cost of a rivet is higher than that of a bolt
Tensile strength of a bolt is lesser than that of a rivet
Bolts are used as a temporary fastening whereas rivets are used as permanent fastenings
Riveting is less noisy than bolting
The maximum slenderness ratio of a steel column, the design of which is governed by wind or seismic forces is
150
180
250
350
2.Compression members composed of two channels back-to-back and separated by a small distance are connected together by riveting so that the minimum slenderness ratio of each member between the connections, does not exceed
40
50
60
70
When the ratio of the moment M to axial load P is greater than L/6, the resultant of the compressive bearing pressure which acts at a distance Y from one side, is given by
y = (L/3) - (M/P)
y = (L/2) - (P/M)
y = (L/2) + (M/P)
y = (L/3) + (M/P)
To the calculated area of cover plates of a built-up beam, an allowance for rivet holes to be added, is
10 %
13 %
15 %
18 %
The safe working pressure for a spherical vessel 1.5 m diameter and having 1.5 cm thick wall not to exceed tensile stress 50kg/cm2, is
16 kg/cm2
18 kg/cm2
20 kg/cm2
22 kg/cm2
The permissible bearing stress in steel, is
1500 kg/cm2
1890 kg/cm2
2025 kg/cm2
2340 kg/cm2
The rolled steel I-sections are most commonly used as beams because these provide
Large moment of inertia with less cross-sectional area
Large moment of resistance as compared to other section
Greater lateral stability
All the above
Column footing is provided
To spread the column load over a larger area
To ensure that intensity of bearing pressure between the column footing and soil does not exceed permissible bearing capacity of the soil
To distribute the column load over soil through the column footing
All the above
The moment-curvature relation at a plastic hinge is
Linear
Parabolic
Constant moment for all curvatures
Constant curvature for all moments
The average shear stress for rolled steel beam section, is
845 kg/cm2
945 kg/cm2
1025 kg/cm2
1500 kg/cm2
The allowable stress in axial tension is generally kept less if thickness of the member is more than
10 mm
12 mm
15 mm
20 mm
If N is the number of rivets in the joint, the strength of a riveted joint against shearing of rivets, is given by
Ps = N × (π/4) d2 × Ps
Ps = N × (d × t × ps)
Ps = N × (p - d) × t × Ps
Ps = N × (P + d) × t × ps
The ratio of longitudinal stress to strain within elastic limit, is known as
Modulus of elasticity
Shear modulus of elasticity
Bulk modulus of elasticity
All the above
A column splice is used to increase
Length of the column
Strength of the column
Cross-sectional area of the column
None of these
Which of the following conditions is to be satisfied both in elastic and plastic analysis?
Equilibrium condition
Yield condition
Plastic moment condition
Mechanism condition
The channels get twisted symmetrically with regard to its axis
Parallel to flanges
Parallel to web
Perpendicular to flanges
Perpendicular to web
A beam may be designed as a cased beam if
Section is of double open channel form with the webs not less than 40 mm apart
Overall depth and width of the steel section do not exceed 750 and 450 mm respectively
Beam is solidly encased in concrete with 10 mm aggregate having 28 days strength 160 kg/cm2
All the above
The sway bracing is designed to transfer
2Vi % of the top panel wind load to bottom bracing
10% of the top panel wind load to bottom bracing
25% of the top panel wind load to bottom bracing
50% of the top panel wind load to bottom bracing
Outstanding length of a compression member consisting of a channel, is measured as
Half of the nominal width
Nominal width of the section
From the edge to the first row of rivets
None of these