If the moment of inertia of a section about its axis is I and its effective sectional area is A, its radius of gyration r about the axis, is
r = I/A
r = √(I/A)
r = (I/A)
r = √(A/I)
Correct Answer :
B. r = √(I/A)
Related Questions
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
The ratio of hydrostatic stress to the volumetric strain within the elastic range, is called
Modulus of elasticity
Shear modulus of elasticity
Bulk modulus of elasticity
All the above
Efficiency of a riveted joint, having the minimum pitch as per IS : 800, is
40 %
50 %
60 %
70 %
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
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
10 mm
The stress in the wall of a thin cylinder subjected to internal pressure, is
Hoop compression
Shear
Torsional shear
Hoop tension
When a tension member consists of two channel sections, the allowance for rivet hole is made for two holes from
Each web
Each flange
Each web or one hole from each flange whichever is more
Each web or one hole from each flange whichever is less
The gross diameter of a rivet is the diameter of
Cold rivet before driving
Rivet after driving
Rivet hole
None of these
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
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)
A simply supported beam carrying a central load, will be safe in deflection if the ratio of its span to depth, is
< 19
< 24
> 19
> 24
The beam outside a wall upto floor level above it, is known as
Rafter
Purlin
Spandrel beam
Lintel
For steel members exposed to weather and not accessible for repainting, the thickness of steel should not be less than
4.5 mm
6 mm
8 mm
10 mm
According to I.S. : 800 - 1871, lacing bars resist transverse shear equal to
1.0% of the axial load
2.0% of the axial load
2.5% of the axial load
3.0% of the axial load
The channels get twisted symmetrically with regard to its axis
Parallel to flanges
Parallel to web
Perpendicular to flanges
Perpendicular to web
The range of economical spacing of trusses varies from
L/3 to L/5
L/4 to 2L/5
L/3 to L/2
2L/5 to 3L/5, where L is span
According to IS : 800-1962 the permissible bending stress in steel slab plates, is
1500 kg/cm2
1420 kg/cm2
2125 kg/cm2
1890 kg/cm2
Lug angles
Are used to reduce the length of connection
Are unequal angles
Increases shear lag
All the above
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 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
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
Tacking rivets in compression plates not exposed to the weather, have a pitch not exceeding 300 mm or
16 times the thickness of outside plate
24 times the thickness of outside plate
32 times the thickness of outside plate
36 times the thickness of outside plate
Tongue plates are provided in a steel girder at
The upper flange
The lower flange
The upper end of the web
The upper and lower ends of the web
The central deflection of a simply supported steel beam of length L with a concentrated load W at the centre, is
WL3/3EI
WL4/3EI
WL3/48EI
5WL4/384EI
The greatest permissible clear dimension of the web of thickness t in the panel of a plate girder, is restricted to
180 t
220 t
230 t
270 t
Maximum permissible slenderness ratio of a member normally acting as a tie in a roof truss, is
180
200
250
350
The spans are considered approximately equal if the longest span does not exceed the shortest span by more than
5 %
10 %
15 %
20 %
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
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
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