Quiz: CIVIL ENGINEERING
Exam: NPCIL-SCINTIFIC ASSISTANT(CIVIL)
Each question carries 1 mark
Negative marking: No negative marking
Time: 10 Minutes
Q1. Soil is compacted at which one of the following when a higher compactive effort produces highest increases in dry density?
(a) Optimum water content
(b) dry side of the optimum moisture content
(c) wet side of the optimum moisture content
(d) saturation moisture content
Q2. Effective stress in a soil is the stress carried by the
(a) Soil mass as whole
(b) pore water present in the voids
(c) Air present in the void
(d) solids present in the soil mass
Q3. The coefficient of permeability increases when
(a) the viscosity of fluid increases
(b) the viscosity of fluid decreases
(c) the temperature condition decreases
(d) length of sample is decreased
Q4. A flownet of a coffer dam foundation has 6 flow channels and 18 equipotential drops. The head of water lost during seepage is 6 m. if the coefficient of permeability of foundation is 4 × 10–5 m/mm, then the seepage loss per metre length of dam will be.
(a) 2.16 × 10–2 m³/day
(b) 6.48 × 10–2 m³/day
(c) 11.52 × 10–2 m³/day
(d) 34.56 × 10–2 m³/day
Q5. Capillary rise is maximum for
(a) coarse grained soils
(b) fine grained soils
(c) well graded soils
(d) gap graded soils
Q6. In the design of two-way slab restrained at all edges, torsional reinforcement required is
(a) 0.75 times the area of steel provided at mid span in the same direction
(b) 0.375 time the area of steel provided at mid span in the same direction
(c) 0.375 time the area of steel provided in the shorter span
Q7. If the average daily water consumption of a city is 24000 cum, the peak hourly demand (of the maximum day) will be
(a) 1000 cum/hr
(b) 1500 cum/hr
(c) 1800 cum /hr
(d) 2700 cum/hr
Q8. Freeman’s formula for estimating the fire demand (Q) in I.p.m. is given by
(a) Q=1136 (P/10+10)
(b) Q=2500 (P/5+10)
(d) Q =3175√P
P = population in thousands
Q9. Consider the following statements:
The basic difference between water pipes and sewer pipes is
- In the material used for the pipes
- In the pressure of the liquid flow
- In the suspended solids they carry
Which of these statements is/are correct?
(a) 1 and 3
(b) 1 only
(c) 2 and 3
(d) 1, 2 and 3
Q10. By using economical of water mains, the benefit obtained is in terms of
(a) minimum pumping cost
(b) use of cheapest pipe
(c) minimum cost of pipe and pumping
(d) none of the above benefit is attained
Sol. With increase in compactive effort the optimum moisture content decrease and dry density increases.
Sol. Effective stress is a function of the particle contact force. Pore water pressure acts uniformly on all sides of the particle and does not cause the soil particle to press against each other.
Sol. According to Kozney Karman
▭(k=1/k_k γ_w/μ e^3/(1+e) d^2 )
▭(k α 1/μ)
Sol. Loss of seepage per meter length
q = k H N_f/N_d
q = 0.0576 × 6/18 × 6
= 0.1152 m^3/day
= 11.52 × 10^(–2) m^3/day
Sol. ▭(h=(4σ cosθ)/(γ_w d) )
For fine grained soils effective size ‘d’ is smaller so it will experience more capillary rise.
Sol. In the design of two way slab restrained at all edges torsional reinforcement is 0.75 times the area of steel provided at mid span in the same direction.
Sol. Maximum hourly consumption of the maximum day.
= 1.5 × ((1.8 q)/24)
= 2.7 × 24000/24
= 2700 cum/hr
Sol. Freeman’s Formula
Q = 1136 (P/10+ 10)
Sol. Cast iron pipes can be used for both water pipe and sewer pipe. However the basic difference is pressure flow.
Sol. By using economical of water mains the benefit obtained is minimum cost of pipe and pumping.