The critical load for a column of length I hinged at both ends and having flexural rigidity El, is given by
Pc = π²EI/l²
Pc = πEI/l²
Pc = πEI/I²
None of these
Correct Answer :
A. Pc = π²EI/l²
Related Questions
According to the Unwin's formula, if t is thickness of the plate in mm, the nominal diameter of the rivet, is
d = 1.91 t
d = 1.91 t2
d = 1.91 √t
d = 1.91 t
Water pressure in a 80 cm water main is 10 kg/cm2. The minimum thickness of the metal required for the water main, not to be stressed more than 200 kg/cm2, is
1 cm
1.5 cm
2 cm
2.5 cm
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
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
2.13 m above the rail level
In case of cantilever fillers, the ratio of the span L to depth d, should not exceed
4
8
12
16
Effective length of a column effectively held in position at both ends and restrained in direction at one end, is
L
0.67 L
0.85 L
1.5 L
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
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
The critical stress on a column for elastic buckling given by Euler's formula, is
fc = π²E/(I/r)²
fc = (I/r)²/ πE
fc = (I/r)/ πE
fc = π²E/(I/r)
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
The moment-curvature relation at a plastic hinge is
Linear
Parabolic
Constant moment for all curvatures
Constant curvature for all moments
Intermediate vertical stiffeners in a plate girder need be provided if the depth of web exceeds
50 t
85 t
200 t
250 t Where t is thickness of web
If M is the moment due to a couple in a bearing plate whose width is b and allowable bending stress is P, the thickness (t) of the bending plate of the column splice, is
t = √[(b × p)/6M]
t = √[6M/(b × p)]
t = 6M/bp
t = √6M/(b × p)
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
As per ISI, rolled steel beam sections are classified into
Two series
Three series
Four series
Five series
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
Pick up the correct statement from the following:
The steel beams placed in plain cement concrete, are known as reinforced beams
The filler joists are generally continuous over three-supports only
Continuous fillers are connected to main beams by means of cleat angles
Continuous fillers are supported by main steel beams
The maximum permissible slenderness ratio of compression member carrying dead and superimposed load, is
180
200
250
350
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
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
For a rectangular section, the ratio of the maximum and average shear stresses, is
1.5
2.0
2.5
3.5
In a built up section carrying a tensile force, the flanges of two channels are turned outward
To simplify the transverse connections
To minimise lacing
To have greater lateral rigidity
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
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
The actual thickness of butt weld as compared to the thickness of plate is usually
More
Less
Equal
None of the above
The diameter of a bolt hole is taken as the nominal diameter of the bolt plus
1.0 mm
1.2 mm
1.4 mm
1.6 mm
The slenderness ratio of lacing bars should not exceed
100
120
145
180
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
A riveted joint many experience
Tearing failure of plates
Splitting failure of plates at the edges
Bearing failure of rivets
All the above
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