Quiz: CIVIL ENGINEERING (03-FEB-2021)
Exam: NPCIL-SCINTIFIC ASSISTANT(CIVIL)
Each question carries 1 mark
Negative marking: No negative marking
Time: 10 Minutes
Q1. When HYSD bars are used in place of mild steel bars in a beam, the bond strength
(a) does not change
(d) becomes zero
Q2. Kinematic viscosity of gases on increase of temperature
(c) remains the same
(d) none of these
Q3. If the dynamic viscosity of a fluid is 0.5 poise and specific gravity is 0.5, then kinematic viscosity of that fluid in stokes is
(d) None of these
Q4. If the relationship between the shear stress τ and the rate of shear strain du/dy is expressed as
Then the fluid with a value of exponent n > 1 is known as
(a) dilatant fluid
(b) pseudoplastic fluid
(c) Newtonian fluid
(d) Bingham plastic
Q5. If for a given basin in a given period, P = precipitation, E = evapotranspiration, R = total runoff and ∆S = increase in the storage of water in the basin, the hydrological water budget equation states
(a) P = R – E ± ∆S
(b) R = P – E – ∆S
(c) P = R + E + ∆S
(d) None of these
Q6. Direct runoff is made up of
(a) Surface runoff, prompt interflow and channel precipitation
(b) surface runoff, infiltration and evapotranspiration
(c) overland flow only
(d) rainfall and evaporation
Q7. For a most economical trapezoidal channel section
(a) hydraulic mean radius equals the depth of flow
(b) hydraulic mean radius equals half the depth of flow
(c) bottom width is twice the depth of flow
(d) bottom width is half the depth of flow
Q8. Leaching is process
(a) By which alkali salts present in the soil are dissolved and drained away
(b) by which alkali salts in soil come up with water
(c) of draining excess water of irrigation
(d) which controls water-logging
Q9. Surveys which are carried out to depict mountains, rivers, water bodies, wooded areas and other cultural details, are known as
(a) cadastral surveys
(b) city surveys
(c) topographical surveys
(d) guide map surveys
Q10. The correction for sag is
(a) always additive
(b) always subtractive
(c) always zero
(d) sometimes additive and sometimes subtractive
Sol. When HYSD bars are used in place of mild steel bars bond stress increased by 60% and bars in compression bond stress increased by 25%.
Sol. In case of gases the cohesion forces and small and molecular momentum transfer predominates with increase in temperature molecular momentum transfer increases and hence kinematic viscosity increase.
Sol. dynamic viscosity (µ) = 0.5 poise
= 0.5 Ns/m^2
G = 0.5
ρ = 0.5 × 1000 = 500 kg/m^3
Kinematic viscosity (V) = µ/ρ
= 10^(–3) m^2/sec
= 10 cm^2/sec = 10 stokes
Sol. τ = k(du/dy)^n
If n > 1 then dilatants fluid.
If n < 1 then pseudo plastic fluid.
P = Precipitation
E = Evapotranspiration
ΔS = Change in storage
Sol. Direct runoff is that part of runoff which enters the stream immediately after the precipitation. It includes surface runoff; prompt interflow and precipitation of the channel.
Sol. For most economical trapezoidal section:
- Hydraulic mean radius equals half the depth of flow
- Top width equal to sum of side of side slope.
- A circle of radius of depth of flow can be inscribed inside it.
Sol. Leaching is the process in which land is flooded with adequate depth of water. The alkali salts present in soil, get dissolved with this water which percolate down to join the water table or are drained away by sub surface drains.
Sol. Survey which are carried out to depict mountains, rivers, water bodies, wooded areas other cultural details are known as topographical survey.
Sol. sag correct = (L (w〖L)〗^2)/(24 P_m^2 )
L → length
P → Pull at the time of measurement
w → weight of tape
sag correction is always subtractive.