DFCCIL (Dedicated Freight Corridor Corporation of India Limited) Exam Date 2021 on September and October 2021 so boost your preparation by attempt this Civil Engineering Miscellaneous quiz for DFCCIL recruitment 2021.
Quiz: Civil Engineering
Each question carries 1 mark
Negative marking: 1/4 mark
Time: 8 Minutes
Q1. Which of the following is CORRECT for the workability of the concrete having the compaction factor of 0.97?
(a) Very Low
Q2. Rise of water able in cohesionless soils up to ground surface. Reduces the net ultimate bearing capacity approximately by
Q3. According to IS 456, the approximate estimated flexural strength (MPa) of concrete of grade M50 (fck = 50 MPa) would be:
Q4. Lacey’s theory is applicable to flow
(a) Through pipes
(b) In concrete lined channels
(c) Over spillways
(d) In alluvial rivers and canals
Q5. Activated sludge process is an example of:
(a) Aerobic attached growth process
(b) Anaerobic suspended growth process
(c) Aerobic suspended growth process
(d) Anaerobic attached growth process
Q6. When observed efflorescence is more than 10% but less than 50% of the exposed area, it is:
(a) Moderate efflorescence
(b) Serious efflorescence
(c) Heavy efflorescence
(d) Light efflorescence
|Degree of Workability||Compaction factor|
|Extremely low||0.65 – 0.7|
|Very low||0.7 – 0.8|
|Low||0.8 – 0.85|
|Medium||0.85 – 0.95|
|High||0.95 – 1|
Sol. For cohesive soil (c=o)
q_u=CN_C+γ_Df N_q+0.5 B_γ N_γ
q_u=γ_Df N_q+0.5 B_γ N_γ
If water table rises to G.L
q_u=γ_Df N_q+0.5B_γ N_γ
q_u=1/2 γ_sat D_f N_q+0.5 B(1/2 γ_sat ) N_γ
→ If water table rises to ground level in sand ultimate bearing capacity is reduced approximate by 50%
Sol. Flexure strength (fc) = 0.7√fck
Sol. Lacey’s theory is applicable to flow in alluvial rivers and canals.
Sol. Activated sludge process is example of aerobic suspended growth system. Sludge generated in secondary sedimentation tank mostly consist of living and active micro-organism, hence it is referred as activated sludge.
For slight efflorescence, it should not cover more than 10% Area of exposed surface.
For moderate efflorescence, it should cover more than 10% but less than 50% of the exposed surface.
For heavy efflorescence, it should cover more than 50% area of the exposed surface.