Design Of Steel Structures Set 15 MCQs

Q1 | The method of design of steel framework for greatest rigidity and economy inweight, is known as

Simply design

Semi-rigid design

Fully rigid design

None of these

Q2 | For a cantilever beam of length built-in at the support and restrained against torsion at the free end, the effective projecting length is

l = 0.7 L

l = 0.75 L

l = 0.85 L

l = 0.5 L

Q3 | The least permissible clear dimension of the web of thickness t in the panel of aplate girder, is restricted to

150 t

160 t

170 t

180 t

Q4 | Bearing stiffeners are provided at(i) The supports(ii) The mid span(iii) The point of application of concentrated loadsThe correct answer is

Only (i)

Both (i) and (ii)

Both (i) and (iii)

(i), (ii) and (iii)

Q5 | Pick up the correct statement from the following:

The slenderness ratio of lacing bars for compression members should not exceed145

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 one-fortieth of its length between inner end rivets

All the above

Q6 | If d is the distance between the flange angles, the vertical stiffeners in plate girders are spaced not greater than

d

1.25 d

1.5 d

1.75 d

Q7 | If d is the distance between the flange angles of a plate girder, vertical stiffeners are provided at a distance not greater than

d but not less than 0.20 d

1.25 d but not less than 0.33 d

1.5 d but not less than 0.33 d

2.0 d but not less than 0.50 d

Q8 | A second horizontal stiffener is always placed at the neutral axis of the girder ifthe thickness of the web is less than

d/250 for structural steel

d/225 for high tensile steel

Both (c) and (b)

Neither (a) nor (b)

Q9 | The strength of ISA 125 = 75 × 10 mm used as a tie member with its longer leg connected at the ends by 27 mm diameter rivets, is

26,000 kg

26,025 kg

26,050 kg

26,075 kg

Q10 | The effect of racking forces is considered in the design of(i) Lateral braces(ii) Chord membersThe correct answer is

Only (i)

Only (ii)

Both (i) and (ii)

None of the above

Q11 | For a column of height fixed in position and direction both at its top and bottom, its effective length, is

L

½ L

2L

Q12 | A tension member, if subjected to possible reversal of stress due to wind, the slenderness ratio of the member should not exceed

180

200

300

350

Q13 | Pick up the correct statement from the following:

Tacking rivets are used if the minimum distance between centres of two adjacent rivets exceeds 12 t or 200 mm, whichever isless

Tacking rivets are not considered to calculate stress

Tacking rivets are provided throughout the length of a compression member composed of two components back to back

All the above

Q14 | For double angles carrying tension, placed back to back and connected to either side of the gusset plate, the sectional area of the section, is equal to cross sectional area of

The section

The section plus area of rivet holes

The section minus area of rivet holes

The section multiplied by the area of the rivet hole

Q15 | If fbt and fc are the co-existent bending tensile stress and shear stress in a member, the equivalent stress fc is

fbt² + fc²)

fbt² + ½fc²)

fbt² + 3fc²)

fbt² - 3fc²)

Q16 | When a large value of radius of gyration is not requiredChannels are placed back to back

Channel flanges are kept inward

Channel flanges are kept outward

None of these

all

Q17 | 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

Q18 | If d is the distance between the flange angles, the vertical stiffeners in plate girders without horizontal stiffeners, are spaced at a distance not less than

0.15 d

0.22 d

0.33 d

0.44 d

Q19 | To minimize 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

Q20 | In factory buildings, the horizontal beams spanning between the wall columns supporting a wall covering, are called

Stringers

Trimmers

Girts

Lintels

Q21 | A structural member subjected to tensile force in a direction parallel to its longitudinal axis, is generally known as

A tie

A tie member

A tension member

All the above

Q22 | If the area of cross-section of a single angle discontinuous strut is 30 cm2 and allowable working stress corresponding to its slenderness ratio is 625 kg/cm2, the safe load carrying capacity of the member, is

10 tonnes

12 tonnes

15 tonnes

18 tonnes

Q23 | 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