With usual notations of the letters, the shear stress fs at any point of the cross-section is given by
fs =FQ/It
fs =Ft/IQ
fs =It/FQ
fs =IF/Qt
Correct Answer :
A. fs =FQ/It
Related Questions
An axial loaded column is supported on a slab base whose projection is 8 cm. If the intensity of pressure from concrete is 40 kg/cm2 and allowable bending stress in slab base is 1890 kg/cm2, the thickness (t) of the slab base, is
t = √(21/64)
t = √(64/21)
t = 21/64
t = 64/21
Normally, the angle of roof truss with asbestos sheets should not be less than
26 ½°
30°
35°
40°
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
Slenderness ratio of a compression member is
Moment of inertia/Radius of gyration
Effective length/Area of cross-section
Radius of gyration/Effective length
Radius of gyration/ Area of cross-section
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)
In a tension member if one or more than one rivet holes are off the line, the failure of the member depends upon:
Pitch
Gauge
Diameter of the rivet holes
All the above
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
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
With a percentage increase of carbon in steel, decreases its
Strength
Hardness
Brittleness
Ductility
On eccentrically loaded columns, the equivalent axial load may be obtained by
Adding the axial load, eccentric load, the product of the bending moment due to eccentric load and the appropriate bending factor
Adding the axial load and eccentric load and subtracting the product of bending moment and appropriate bending factor
Dividing the sum of axial load and eccentric load by the product of the bending moment and appropriate bending factor
None of these
The bending moment for filler joists at the middle of an intermediate span, is
WL²/10
- WL²/10
- WL²/12
WL²/12
The internal pressure coefficient on walls for buildings with large permeability is taken as
± 0.2
±0.5
± 0.7
0
The most commonly used sections in lateral system to carry shear force in built up columns, are
Rolled steel flats
Rolled angles
Rolled channels
All the above
A major beam in a building structure, is known as
A girder
A floor beam
A main beam
All the above
The effective length of a weld, is taken as the actual length
Minus the size of weld
Minus twice the size of weld
Plus the size of weld
Plus twice the size of weld
Factor of safety is the ratio of
Yield stress to working stress
Tensile stress to working stress
Compressive stress to working stress
Bearing stress to working stress
The effective length of a compression member of length L, held in position and restrained in direction at both ends, is
L
0.67 L
0.85 L
1.5 L
Pick up the correct statement from the following:
The slenderness ratio of lacing bars for compression members should not exceed 145
The minimum width of lacing bar connected with rivets of nominal diameter 16 mm, is kept 50 mm
The minimum thickness of a flat lacing bar is kept equal to onefortieth of its length between inner end rivets
All the above
When plates are exposed to weather, tacking rivets are provided at a pitch in line not exceeding (where t is the thickness of the outside plate).
8 t
16 t
24 t
32 t
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)
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
Effective sectional area of a compression member is:
Gross sectional area - area of rivet hole
Gross sectional area + area of rivet hole
Gross sectional area × area of rivet hole
Gross sectional area + area of rivet hole
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
If W and L are the total superimposed load and the span of a plate girder in metres, the approximate self weight (W) of the girder, is taken as
M = WL/100
M = WL/200
M = WL/300
M = WL/400
The average shear stress for rolled steel beam section, is
845 kg/cm2
945 kg/cm2
1025 kg/cm2
1500 kg/cm2
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
In plastic analysis, the shape factor for circular sections, is
1.5
1.6
1.697
None of these
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
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
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