Quiz: Civil Engineering
Exam: DFCCIL
Topic: Steel Structure
Each question carries 1 mark
Negative marking: 1/4 mark
Time: 10 Minutes
Q1. The permissible bending stress in working stress method of design of column base is considered equal to
(a) 0.87fy
(b) 0.75fy
(c) 0.60fy
(d) 0.67fy
Q2. The shape factor for a diamond section is
(a) 1.00
(b) 2.00
(c) 1.50
(d) 2.50
Q3. For the fillet weld of size ‘S’ shown in the adjoining figure the effective throat thickness is
(a) 0.61 S
(b) 0.63 S
(c) 0.65 S
(d) 0.75 S
Q4. Prying forces are
(a) tensile forces due to the flexibility of connected parts
(b) Shearing force on the bolts because of the joints
(c) forces due the friction between connected parts
(d) Bending force on the bolts because of the joints.
Q5. A column splice is used to increase:
(a) strength of column
(b) cross-section area of column
(c) length of column
(d) None of these
Q6. Pick the wrongly written assumption taken in analysis of riveted joints:
(a) Total load on the joint is equally shared by all rivets.
(b) Bending moment is not taken into considered
(c) Uniform stress distribution in plates is not consideration
(d) Friction in plate is negligible
Q7. The maximum permissible stress in shear for power driver shop rivet is
(a) 80 N/mm²
(b) 90 N/mm²
(c) 250 N/mm²
(d) 100 N/mm²
Q8. The diameter of a rivet connecting plate of thickness 16 mm. by Unwin’s formula is-
(a) 24 mm
(b) 22 mm
(c) 28 mm
(d) None of these
Q9. What is serviceability?
(a) It refers to condition when structure is not usable
(b) It refers to services offered in the structure
(c) It means that the structure should perform satisfactorily under different loads, without
discomfort to user
(d) It means that structure should be economically viable
Q10. Compression members always tend to buckle in the direction of the:
(a) Perpendicular to the axis of load,
(b) Minimum cross-section
(c) Least radius of gyration
(d) Axis of load
Solutions
S1. Ans.(b)
Sol.
| Sol. | Cases | Permissible stress |
| 1. | In bearing (except at support) | 0.75fy |
| 2. | In bending | 0.66fy |
| 3. | Axial tension & compression | 0.60fy |
S2. Ans.(b)
Sol. The shape factor for a diamond section is 2.00.
S3. Ans.(c)
Sol. ▭(effective throat thickness (t)=K.S)
S = size of weld
‘k’ depends upon angle between fusion
Here, angle of fusion given = 99°
| Angle of fusion | K |
| 60°- 90° | 0.70 |
| 91° – 100° | 0.65 |
| 101° – 106° | 0.60 |
| 107° – 113° | 0.55 |
| 114° – 120° | 0.50 |
Hence ▭(t=0.65 S)
→ effective throat thickness should not be less than 3 mm.
S4. Ans.(a)
Sol. Prying forces are tensile force due to the flexibility of connected parts.
S5. Ans.(c)
Sol. A column splice means joining the two parts of a column. It is used to increase the length of the column.
S6. Ans.(c)
Sol. Assumption in the design of riveted connection.
– The rivet hole is assumed to be filled completely by the rivet.
– Rivets are assumed to be stressed equally.
– Stress in plate is assumed to be uniform.
– Friction between the plates is negligible
– Bending of rivet is neglected
– Shear stress is assumed to be uniformly distributed over the gross cross – section area of the rivet
– Bearing stress is uniform between plates and rivets.
S7. Ans.(d)
Sol.
Shop rivet Axial tension Shear Bearing
Power driven 100 MPa 100 MPa 300 MPa
Hand driven 80 MPa 80 MPa 250 MPaS8. Ans.(a)
Sol. As per Unwin’s formula →
Diameter of rivet, d(mm) = 6.01 √(t_min )
Given, minimum thickness of plate t_min = 16 mm.
Hence, d = 6.01 √16
= 6.01×4
▭(d=24.04≈24 mm.)
S9. Ans.(c)
Sol. Serviceability is related to utility of structure. The structure should perform satisfactorily under service loads, without discomfort to user due to excessive deflection, cracking, vibration etc.
S10. Ans.(c)
Sol. A section buckles about the minor principle axis. For minor principle axis, area of moment of inertia is minimum, thus the radius of gyration is minimum. Hence, the compression members always tend to buckle in the direction of the least radius of gyration.
