When a large value of radius of gyration is not required
Channels are placed back to back
Channel flanges are kept inward
Channel flanges are kept outward
None of these
Correct Answer :
B. Channel flanges are kept inward
Related Questions
Maximum permissible slenderness ratio of a member normally acting as a tie in a roof truss, is
180
200
250
350
The strength of a riveted lap joint is equal to its
Shearing strength
Bearing strength
Tearing strength
Least of (a), (b) and (c)
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 connection of one beam to another beam by means of an angle at the bottom and an angle at the top, is known as
Unstiffened seated connection
Stiffened seated connection
Seated connection
None of these
For a standard 45° fillet, the ratio of size of fillet to throat thickness is
1 : 1
1 : √2
√2 : 1
2 : 1
Bolts are most suitable to carry
Shear
Bending
Axial tension
Shear and bending
The spans are considered approximately equal if the longest span does not exceed the shortest span by more than
5 %
10 %
15 %
20 %
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
Battening is preferable when the (i) Column carries axial load only (ii) Space between the two main components is not very large (iii) Column is eccentrically loaded The correct answer is
Only (i)
Only (iii)
(i) and (ii)
(ii) and (iii)
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
A compression member consisting of angle sections may be a
Continuous member
Discontinuous single angle strut
Discontinuous double angle strut
All the above
Bulb angles are used in
Column building
Bridge building
Ship building
Water tank building
The basic wind speed is specified at a height 'h' above mean ground level in an open terrain. The value of 'h' is
10 m
20 m
25 m
50 m
Rise of a Jack arch is kept about
1/2 to 1/3 of the span
1/3 to 1/4 of the span
1/4 to 1/8 of the span
1/8 to 1/12 of the span
Length of an outstanding leg of a vertical stiffener, may be taken equal to
1/10th of clear depth of the girder plus 15 mm
1/20th of clear depth of the girder plus 20 mm
1/25th of clear depth of the girder plus 25 mm
1/30th of clear depth of the girder plus 50 mm
Which of the following types of riveted joint is free from bending stresses?
Lap joint
Butt joint with single cover plate
Butt joint with double cover plates
None of the above
Normally, the angle of roof truss with asbestos sheets should not be less than
26 ½°
30°
35°
40°
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 %
If p and d are pitch and gross diameter of rivets, the efficiency (η) of the riveted joint, is given by
η = p/p - d
η = p/p + d
η = p - d/p
η = p + d/p
Economical depth of a plate girder corresponds to
Minimum weight
Minimum depth
Maximum weight
Minimum thickness of web
The failure of a web plate takes place by yielding if the ratio of the clear depth to thickness of the web, is less than
45
55
62
82
The stress in the wall of a thin cylinder subjected to internal pressure, is
Hoop compression
Shear
Torsional shear
Hoop tension
If f is the maximum allowable bending stress in a tension member whose radius of gyration is r and depth is 2y, the required cross sectional area A is given by
A = My/fr²
A = My²/fr²
A = My/fr
A = My/f²r²
Lug angles
Are used to reduce the length of connection
Are unequal angles
Increases shear lag
All the above
The gross diameter of a rivet is the diameter of
Cold rivet before driving
Rivet after driving
Rivet hole
None of these
The cross-section of a standard fillet is a triangle whose base angles are
45° and 45°
30° and 60°
40° and 50°
20° and 70°
Design of a riveted joint is based on the assumption:
Bending stress in rivets is accounted for
Riveted hole is assumed to be completely filled by the rivet
Stress in the plate in not uniform
Friction between plates is taken into account
A circular column section is generally not used in actual practice because
It is uneconomical
It cannot carry the load safely
It is difficult to connect beams to the round sections
All of the above
The statical method of plastic analysis satisfies
Equilibrium and mechanism conditions
Equilibrium and plastic moment conditions
Mechanism and plastic moment conditions
Equilibrium condition only
IS : 800 - 1971 recommends that in a splice plate the number of rivets carrying calculated shear stress through a packing greater than 6 mm thick, is to be increased by 2.5% for every
1.00 mm thickness of packing
1.50 mm thickness of packing
2.0 mm thickness of packing
2.50 mm thickness of packing