Design Of Steel Structures Set 17 MCQs

Q1 | For a cantilever beam of length continuous at the support and unrestrained against torsion at the support and free at the end, the effective length is equal to

l = L

l = 2L

l = 0.5L

l = 3L

Q2 | Pick up the correct statement from the following:

When the gauge distance is larger than the pitch, the failure of the section may occur in a zig-zag line

When the gauge distance is smaller than the pitch, the failure of the section may occur in a straight right angle section through the centre of rivet holes

When the gauge distance and pitch are both equal, the failure to the section becomes more likely as the diameter of the holesincreases

All the above

Q3 | If the thickness of plate to be connected by a rivet is 16 mm, then suitable sizeof rivet as per Unwin's formula will be

16 mm

20 mm

24 mm

27 mm

Q4 | Angle of inclination of the lacing bar with the longitudinal axis of the columnshould preferably be between

10° to 30°

30° to 40°

40° to 70°

90°

Q5 | The internal pressure coefficient on walls for buildings with large permeability istaken as

± 0.2

±0.5

± 0.7

Q6 | The centrifugal force due to curvature of track is assumed to act on the bridge at aheight 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

Q7 | According to IS Specifications, the effective length of a column effectively held in position at both ends and restrained in direction at one end is taken as

0.67 L

0.8 L

L

1.5 L

Q8 | 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 M/(b × p)]

t = 6M/bp

t M/(b × p)

Q9 | Allowable working stress corresponding to the slenderness ratio of double angles placed back to back and connected to one side of a gusset plate, is reduced to

50 %

60 %

70 %

80 %

Q10 | The critical stress on a column for elastic buckling given by Euler's formula, is

fc = ²E/(I/r)²

fc = (I/r)²/

fc = (I/r)/

fc = ²E/(I/r)

Q11 | When a tension member is made of four angles with a plate as a web, the allowance for holes is made as

Two holes for each angle and one hole for the web

One hole for each angle and one hole for the web

One hole for each angle and two holes for the web

Two holes for each angle and two holes for theweb

Q12 | To keep the intensity of bearing pressure between the column base and concrete compressive and to vary from zero to 2P/BL, the ratio of the moment M to the axial load P should be

L/2

L/3

L/4

L/6

Q13 | The spans are considered approximately equal if the longest span does not exceed the shortest span by more than

5 %

10 %

15 %

20 %

Q14 | The mechanism method and the statical method give

Lower and upper bounds respectively on the strength ofstructure

Upper and lower bounds respectively on the strength ofstructure

Lower bound on the strength ofstructure

Upper bound on the strength of structure

Q15 | The maximum spacing of vertical stiffeners is (Where d is the distance between flange angles)

1.33 d

1.25 d

1.5 d

1.75 d

Q16 | 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

Q17 | The effective length of a double angle strut with angles placed back to back and connected to both the sides of a gusset plate, by not less than two rivets, is

0.5 L

0.67 L

0.85 L

2 L

Q18 | 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 isspan

Q19 | The maximum slenderness ratio of a steel column, the design of which is governed by wind or seismic forces is

150

180

250

350

Q20 | 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

Q21 | For steel members not exposed to weather, the thickness of steel should not be lessthan

4.5 mm

6 mm

8 mm

10 mm

Q22 | 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

Q23 | If a pair of angles placed back to back in tension are connected by one leg of each angle, the net effective area of the section, is

a - [b/{1 + 0.35 (b/a)}]

a + [b/{1 + 0.35 (b/a)}]

a - [b/{1 + 0.2 (b/a)}]

a + [b/{1 + 0.2 (b/a)}]

Q24 | Secant formula for direct stress in compression, is applicable only for slendernessratio upto

120

130

140

150