Essential 100 Objective Questions On Design Of Steel Structures
1.For a standard 45� fillet, the ratio of size of fillet to throat thickness is
1:1
1 : V2
V2 : 1
2: 1
ANSWER : : V2 : 1
2.When the axis of load lies in the plane of rivet group, then the rivets are subjected to
only shear stresses
only tensile stresses
both (a) and (b)
none of the above
ANSWER : : only shear stresses
3.If the thickness of thinnest outside plate is 10 mm, then the maximum pitch of rivets in tension will be taken as
120 mm
160 mm
200 mm
300 mm
ANSWER : : 160 mm
4.Efficiency of a riveted joint, having the minimum pitch as per IS : 800, is
40%
50%
60%
70%
ANSWER : : 60%
5.Minimum pitch of the rivets shall not be less than
1.5 d
2.0 d
2.5 d
3.0 d
ANSWER : re d is gross diameter of rivet
7.Bending compressive and tensile stresses respectively are calculated based on
net area and gross area
gross area and net area
net area in both cases
gross area in both cases
ANSWER : : gross area and net area
8.As compared to field rivets, the shop rivets are
stronger
weaker
equally strong
any of the above
ANSWER : : stronger
9.The difference between gross diameter and nominal diameter for the rivets up to 25 mm diameter is
1.0 mm
1.5 mm
2.0 mm
2.5 mm
ANSWER : : 1.5 mm
10.When the bolts are subjected to reversal of stresses, the most suitable type of bolt is
black bolt
ordinary unfinished bolt
turned and fitted bolt
high strength bolt
ANSWER : : high strength bolt
11.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 fastenings whereas rivets are used as permanent fastenings.
Riveting is less noisy than bolting.
ANSWER : : Bolts are used as a temporary fastenings whereas rivets are used as permanent fastenings.
12.A butt weld is specified by
effective throat thickness
plate thickness
size of weld
penetration thickness
ANSWER : : effective throat thickness
13.The actual thickness of butt weld as compared to the thickness of plate is usually
more
less
equal
none of the above
ANSWER : : more
14.Diameter of a bolt hole is usually taken as
gross diameter of bolt
nominal diameter + 1.5 mm
nominal diameter + 2.0 mm
nominal diameter of bolt
ANSWER : : nominal diameter + 1.5 mm
15.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
ANSWER : : it is difficult to connect beams to the round sections
16.In a gusseted base, when the end of the column is machined for complete bearing on the base plate, then the axial load is assumed to be transferred to base plate
fully by direct bearing
fully through fastenings
50% by direct bearing and 50% through fastenings
75% by direct bearing and 25% through fastenings
ANSWER : : 50% by direct bearing and 50% through fastenings
17.If the thickness of plate to be connected by a rivet is 16 mm, then suitable size of rivet as per Unwin’s formula will be
16 mm
20 mm
24 mm
27 mm
ANSWER : : 24 mm
18.By providing sufficient edge distance, which of the following failures of riveted joint can be avoided ?
tension failure of the plate
shear failure of the rivet
shear failure of the plate
crushing failure of the rivet
ANSWER : : shear failure of the plate
19.The slenderness ratio of a column supported throughout its length by a masonry wall is
zero
10
100
infinity
ANSWER : : zero
20.In the cross-section of a weld, throat is the
minimum dimension
average dimension
maximum dimension
none of the above
ANSWER : : minimum dimension
21.The effective length of a fillet weld should not be less than
two times the weld size
four times the weld size
six times the weld size
weld size
ANSWER : : four times the weld size
22.According to IS Specifications, the maximum pitch of rivets in compression is
lesser of 200 mm and 12 t
lesser of 200 mm and 161
lesser of 300 mm and 32 t
lesser of 3 00 mm and 24 t
ANSWER : re t is thickness of thinnest outside plate or angle
23.Bolts are most suitable to carry
shear
bending
axial tension
shear and bending
ANSWER : : axial tension
24.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
ANSWER : : butt joint with double cover plates
25.According to IS:800, in the Merchant Rankine formula the value of imperfection index (n) is
1.0
1.4
1.8
2.0
ANSWER : : 1.4
26.As per IS : 800, for compression flange, the out stand of flange plates should not exceed
121
161
201
251
ANSWER : re t = thickness of thinnest flange plate
27.Shear buckling of web in a plate girder is prevented by using
vertical intermediate stiffener
horizontal stiffener at neutral axis
bearing stiffener
none of the above
ANSWER : : vertical intermediate stiffener
28.Economical depth of a plate girder corresponds to
minimum weight
minimum depth
maximum weight
minimum thickness of web
ANSWER : : minimum weight
29.Bearing stiffener in a plate girder is used to
transfer the load from the top flange to the bottom one
prevent buckling of web
decrease the effective depth of web
prevent excessive deflection
ANSWER : : prevent buckling of web
30.Horizontal stiffener in a plate girder is provided to safeguard against
shear buckling of web plate
compression buckling of web plate
yielding
all of the above
ANSWER : : compression buckling of web plate
31.Gantry girders are designed to resist
lateral loads
longitudinal loads and vertical loads
lateral, longitudinal and vertical loads
lateral and longitudinal loads
ANSWER : : lateral, longitudinal and vertical loads
32.Minimum thickness of web in a plate girder, when the plate is accessible and also exposed to weather, is
5 mm
6 mm
8 mm
10mm
ANSWER : : 6 mm
33.The maximum slenderness ratio of a compression member carrying both dead and superimposed load is
180
200
250
350
ANSWER : : 180
34.The best arrangement to provide unified behavior in built up steel columns is by
lacing
battening
tie plates
perforated cover plates
ANSWER : : lacing
35.The web crippling due to excessive bearing stress can be avoided by
increasing the web thickness
providing suitable stiffeners
increasing the length of the bearing plates
none of the above
ANSWER : : increasing the length of the bearing plates
36.Lacing bars in a steel column should be designed to resist
bending moment due to 2.5% of the column load
shear force due to 2.5% of the column load
2.5% of the column load
both (a) and (b)
ANSWER : : shear force due to 2.5% of the column load
37.The maximum slenderness ratio of a steel column, the design of which is governed by wind or seismic forces is
150
180
250
350
ANSWER : : 250
38.The slenderness ratio of lacing bars should not exceed
100
120
145
180
ANSWER : : 145
39.The effective length of a battened column is increased by
5%
10%
15%
20%
ANSWER : : 10%
40.The effective length of a battened strut effectively held in position at both ends but not restrained in direction is taken as
1.8 L
L
1.1 L
1.5 L
ANSWER : : 1.1 L
41.Minimum spacing of vertical stiffeners is limited to
d/4
d/3
d/2
2d/3
ANSWER : re d is the distance between flange angles
42.Intermediate vertical stiffeners in a plate girder need be provided if the depth of web exceeds
501
851
200t
2501
ANSWER : re t is thickness of web
43.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)
ANSWER : : (i) and (ii)
44.Angle of inclination of the lacing bar with the longitudinal axis of the column should preferably be between
10� to 30�
30� to 40�
40� to 70�
90�
ANSWER : : 40� to 70�
45.The forces acting on the web splice of a plate girder are
axial forces
shear and axial forces
shear and bending forces
axial and bending forces
ANSWER : : shear and bending forces
46.The use of tie plates in laced columns is
prohibited
not prohibited
permitted at start and end of lacing system only
permitted between two parts of the lacing
ANSWER : : permitted at start and end of lacing system only
47.The overlap of batten plates with the main members in welded connections should be more than
3t
4t
6t
8t
ANSWER : re t = thickness of the batten plate
48.If the 20 mm rivets are used in lacing bars, then the minimum width of lacing bar should be
40mm
60mm
80mm
100mm
ANSWER : : 60mm
49.The bracing between two columns of a steel tank will be designed to resist
horizontal shear due to wind or earthquake only
horizontal, shear due to wind or earthquake + 2.5% of column loads
column loads + 2.5% of horizontal shear due to wind or earthquake
column loads + full horizontal shear due to wind or earthquake
ANSWER : : horizontal, shear due to wind or earthquake + 2.5% of column loads
50.The capacity of the smallest pressed steel tank is
1000 litre
1650 litre
1950 litre
2450 litre
ANSWER : : 1950 litre
51.For the buildings having a low permeability, the internal wind pressure acting normal to the wall and roof surfaces is taken as
zero
�0.2p
� 0.5 p
�0.7p
ANSWER : re p is basic wind pressure
52.The number of seismic zones in which the country has been divided are
3
5
6
7
ANSWER : : 5
53.To minimise the total cost of a roof truss, the ratio of the cost of truss to the cost of purlins shall be
1
2
3
4
ANSWER : : 2
54.Normally, the angle of roof truss with asbestos sheets should not be less than
26’/2�
30�
35�
40�
ANSWER : : 30�
55.Which of the following sections should preferably be used at places where torsion occurs ?
angle section
channel section
box type section
any of the above
ANSWER : : box type section
56.Minimum pitch provided in riveted steel tanks is
1.5 d
2.0 d
2.5 d
3.0 d
ANSWER : re d is diameter of rivets
57.As per IS : 875, for the purposes of specifying basic wind velocity, the country has been divided into
4 zones
5 zones
6 zones
7 zones
ANSWER : : 6 zones
58.The internal pressure coefficient on walls for buildings with large permeability is taken as
� 0.2
�0.5
� 0.7
0
ANSWER : : � 0.7
59.The maximum permissible span of asbestos cement sheets is
650 mm
810 mm
1250 mm
1680 mm
ANSWER : : 1680 mm
60.The risk coefficient k, depends on
mean probable design life of structures
basic wind speed
both (a) and (b)
none of the above
ANSWER : : both (a) and (b)
61.The range of economical spacing of trusses varies from
L/3 to L/5
L/4to2L/5
L/3 to L/2
2L/5 to 3L/5 where L is span
ANSWER : : L/3 to L/5
62.Steel tanks are mainly designed for
weight of tank
wind pressure
water pressure
earthquake forces
ANSWER : : water pressure
63.Area of openings for buildings of large permeability is more than
10% of wall area
20% of wall area
30% of wall area
50% of wall area
ANSWER : : 20% of wall area
64.Generally the purlins are placed at the panel points so as to avoid
axial force in rafter
shear force in rafter
deflection of rafter
bending moment in rafter
ANSWER : : bending moment in rafter
65.The external wind pressure acting on a roof depends on
degree of permeability of roof
slope of roof
both (a) and (b)
none of the above
ANSWER : : slope of roof
66.The live load for a sloping roof with slope 15�, where access is not provided to roof, is taken as
0.65 kN/m2
0.75 kN/m2
1.35 kN/m2
1.50 kN/m2
ANSWER : : 0.65 kN/m2
67.The maximum spacing of vertical stiffeners is
1.33d
1.25 d
1.5 d
1.75d
ANSWER : re d is the distance between flange angles
68.The allowable tensile stress in structural mild steel plates for steel tank is assumed as
95.0 MPa on net area
105.5 MPa on net area
105.5 MPa on gross area
150.0 MPa on gross area
ANSWER : : 105.5 MPa on net area
69.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
ANSWER : : 10 m
70.The minimum thickness of plates in a steel stack should be
4mm
5 mm
6 mm
8 mm
ANSWER : : 6 mm
71.Rivets connecting flange angles to cover plates in a plate girder are subjected to
horizontal shear only
vertical load only
both (a) and (b)
none of the above
ANSWER : : horizontal shear only
72.The relation between intensity of wind pressure p and velocity of wind V is taken as
pa V
paV2
p a (1/V)
paV”2
ANSWER : : paV2
73.In case of timber structures, the form factor for solid circular cross-section is taken as
1.18
1.414
1.67
1.81
ANSWER : : 1.18
74.Shape factor is a property which depends
only on the ultimate stress of the material
only on the yield stress of the material
only on the geometry of the section
both on the yield stress and ultimate stress of material
ANSWER : : only on the geometry of the section
75.In the virtual work method, the virtual quantity is
displacement
load
slope
moment
ANSWER : : displacement
76.Hudson’s formula gives the dead weight of a truss bridge as a function of
bottom chord area
top chord area
effective span of bridge
heaviest axle load of engine
ANSWER : : bottom chord area
77.The statical method of plastic analysis satisfies
equilibrium and mechanism conditions
equilibrium and plastic moment conditions
mechanism and plastic moment conditions
equilibrium condition only
ANSWER : : equilibrium and plastic moment conditions
78.The portal bracing in a truss bridge is used to
transfer load from top of end posts to bearings
keep the rectangular shape of the bridge cross-section
stiffen the structure laterally
prevent the sideways buckling of top chord
ANSWER : : transfer load from top of end posts to bearings
79.The mechanism method of plastic analysis satisfies
equilibrium and mechanism conditions
equilibrium and plastic moment conditions
mechanism and plastic moment conditions
equilibrium condition only
ANSWER : : equilibrium and mechanism conditions
80.If the loaded length of span in meters of a railway steel bridge carrying a single track is 6 m, then impact factor is taken as
0
0.5
between 0.5 and 1.0
1.0
ANSWER : : between 0.5 and 1.0
81.The mechanism method and the statical method give
lower and upper bounds respectively on the strength of structure
upper and lower bounds respectively on the strength of structure
lower bound on the strength of structure
upper bound on the strength of structure
ANSWER : : upper and lower bounds respectively on the strength of structure
82.The elastic strain for steel is about
1/12 of strain at the initiation of strain hardening and about 1/120 of maxi-mum strain
1/2 of strain at the initiation of strain hardening and about 1/12 of maxi-mum strain
1/12 of strain at the initiation of strain hardening and 1/200 of maximum strain
1/24 of strain at the initiation of strain hardening and about 1/200 of maximum strain
ANSWER : : 1/12 of strain at the initiation of strain hardening and 1/200 of maximum strain
83.In case of timber structures, the simple bending formula M = fz may be applied for
rectangular beams up to 300 mm depth
all rectangular beams
solid circular beams only
all square cross-section beams
ANSWER : s: a
84.The bracing provided in the plane of end posts is called
sway bracing
portal bracing
top lateral bracing
bottom lateral bracing
ANSWER : : portal bracing
85.The centrifugal force due to curvature of track is assumed to act on the bridge at a height of
1.23 m above the rail level
1.50 m above the rail level
1.83 m above the rail level
2.13m above the rail level
ANSWER : : 1.83 m above the rail level
86.Load factor is
always equal to factor of safety
always less than factor of safety
always greater than factor of safety
sometimes greater than factor of safety
ANSWER : : always greater than factor of safety
87.The ratio of plastic section modulus to elastic section modulus
is equal to 1
is always less than 1
is always greater than 1
can be less than 1
ANSWER : : is always greater than 1
88.Study the following statements. i) Top lateral bracing prevents the sidesway buckling of the chord. ii) Sway bracing keeps the rectangular shape of the bridge cross-section. iii) Sway bracing transfers the load from top of end posts to bearings. The correct answer is
only (i)
both (i) and (ii)
both (i) aad (iii)
all (i), (ii) and (iii)
ANSWER : : both (i) and (ii)
89.Which of the following conditions is to be satisfied both in elastic and plastic analysis ?
equilibrium condition
yield condition
plastic moment condition
mechanism condition
ANSWER : : equilibrium condition
90.The least dimension in case of a circular column of diameter D is taken as
0.5 D
0.68 D
0.88 D
D
ANSWER : : 0.88 D
91.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
ANSWER : s: a
92.As per IS:800, in the plastic design, which of the following pairs are correctly matched? Working Loads Load factor (i) Dead load 1.7 (ii) Dead Load + imposed load 1.7 (iii) Dead load + load due to wind or 1.3 seismic forces (iv) Dead load + imposed load + load 1.7 due to wind or seismic forces Of these statements
(i) and (ii) are correct
(i), (ii) and (iii) are correct
(ii) and (iii) are correct
only (i) is correct
ANSWER : : (i) and (ii) are correct
93.If the floor is supported at or near the bottom but top chords of a bridge are not braced, then the bridge is called
deck type
through type
half through type
double deck type
ANSWER : : half through type
94.The diameter of base of conical flare of a steel stack is
less than d
equal to d
more than d
any of the above
ANSWER : re d is the diameter of the cylindrical part
95.compression force in two end posts The pin of a rocker bearing in a bridge is designed for
bearing and shear
bending and shear
bearing and bending
bearing, shear and bending
ANSWER : : bearing, shear and bending
96.Other conditions being same, the load factor in indeterminate structures is
equal to load factor in determinate structures
more than the load factor in determinate structures
less than the load factor in determinate structures
unpredictable
ANSWER : : more than the load factor in determinate structures
97.The moment-curvature relation at a plastic hinge is
linear
parabolic
constant moment for all curvatures
constant curvature for all moments
ANSWER : : constant moment for all curvatures
98.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
ANSWER : : 50% of the top panel wind load to bottom bracing
99.Lug angles
are used to reduce the length of connection.
are unequal angles.
increases shear lag.
all the above
ANSWER : : are used to reduce the length of connection.
100.The connection of intermediate vertical stiffeners to the web, not subjected to external loads, shall be designed for a minimum shear force (kN/m) of
75 t2/h
125 t3/h2
125 t2/h
175 t2/h
ANSWER : re, t = the web thickness in mm h = the out stand of stiffener in mm
101.The minimum thickness of a steel plate, which is directly exposed to weather and is not accessible for cleaning and repainting, should be:
4.5 mm
6 mm
8 mm
10 mm
ANSWER : : 8 mm
103.A steel beam supporting loads from the floor slab as well as from wall is termed as
stringer beam
lintel beam
spandrel beam
header beam
ANSWER : : spandrel beam
104.In case of plastic design, the calculated maximum shear capacity of a beam as per IS:800 shall be
0.55 Awfy
0.65 Awfy
0.75 Awfy
0.85 Awfy
ANSWER : re, Aw = effective cross-sectional area resisting shear fy = yield stress of the steel
105.Pitch of tacking rivets, when double angles connected back to back and acting as tension members should not be more than
500 mm
600 mm
1000 mm
300 mm
ANSWER : : 1000 mm
106.For rivets in tension with counter-sunk heads, the tensile value shall be
reduced by 25 %
reduced by 33.3%
increased by 25 %
increased by 33.3 %
ANSWER : : reduced by 33.3%
107.For a compression member with double angle section, which of the following section will give larger value of minimum radius of gyration?
equal angles back to back
unqual legged angles with long legs back to back
unequal legged angles with short legs back to back
both (b) or (c)
ANSWER : : unqual legged angles with long legs back to back
108.In moment resistant connections, the moment resistance of riveted connection depends upon
shear in rivets
compression in rivets
tension in rivets
strength of rivets in bearing
ANSWER : : tension in rivets
109.The allowable shear stress in the web of mild steel beams decreases with
decrease in h/t ratio
increase in h/t ratio
decrease in thickness
increase in height
ANSWER : re ‘h’ is height and t is thickness