QUIZ : CIVIL ENGINEERING (23-12-2020)

Quiz: Civil Engineering
Exam: SSC-JE
Topic: MISCELLANEOUS

Each question carries 1 mark
Negative marking: 1/4 mark
Time: 10 Minutes

Q1. The term nominal stress in stress-strain curve for mild steel implies
(a) average stress
(b) actual stress
(c) yield stress
(d) stress at necking
Q2. Graphical representation of which one of the following theories is by an ellipse?
(a) Maximum principal strain theory
(b) Distortion energy theory
(c) Maximum shear stress theory
(d) None of these
Q3. The maximum deflection of simply supported beam occurs at zero
(a) bending moment location
(b) shear force location
(c) slope location
(d) shear force location and also zero bending moment location
Q4. A soil sample has natural moisture content ‘w’, void ratio ‘e’ and specific gravity of soil solids ‘Gs’. The bulk unit weight of soil ‘γ’, is given by (‘γ’, is unit weight of water)
(a) ((1-w) G_s γ_w)/((1+e))
(b) ((1-w) G_s γ_w)/((1-e))
(c) ((1+w) G_s γ_w)/((1+e))
(d) ((1-w) G_s γ_w)/((1+e))
Q5. Approximate ratios of the permeabilities of two clean soils having D10 = 0.6 mm and D10 = 0.3 mm respectively is
(a) 4.0
(b) 3.75
(c) 4.25
(d) 3.5
Q6. The soils most susceptible to liquefaction are
(a) saturated dense sands
(b) Saturated loose sands
(c) saturated clays of uniform size
(d) saturated gravels and cobbles
Q7. The upstream slope of an earth dam under steady seepage condition is
(a) equipotential line
(b) phreatic line
(c) flow line
(d) seepage line
Q8. Rankine’s theory of earth pressure assumes that the back of the wall is
(a) plane and smooth
(b) plane and rough
(c) vertical and smooth
(d) vertical and rough
Q9. Negative skin friction on a pile under vertical compressive load acts
(a) Downwards and increases the load carrying capacity of the pile
(b) Downwards and reduces the load carrying capacity of pile
(c) upwards and increases the load carrying capacity of the pile
(d) downwards and maintains the same load carrying capacity of the pile
Q10. Which one of the following methods gives the best estimate of population growth of a community with limited land area for future expansion?
(a) Arithmetical increase method
(b) Geometrical increase method
(c) Incremental increase method
(d) Logistic method

Solutions
S1. Ans.(a)
Sol. Nominal stress=Load/(original area)
Actual stress=Load/(Actual area)
→ Nominal stress of mild steel also implies average stress.

S2. Ans.(b)
Sol. Graphical representation of maximum shear strain energy theory or detorsion energy theory is ellipse

S3. Ans.(c)
Sol. In Simply supported beam

                         At point C deflection is maximum & slope is zero

S4. Ans.(c)
Sol. γ_d=γ_b/(1+ω)=(Gγ_w)/(1+e)
γ_b=(Gγ_w (1+ω ))/(1+e)

S5. Ans.(a)
Sol. ▭(K=100D_10^2 )
K_1/K_2 =((D_10 )_1^2)/((D_10 )_2^2 )
K_1/K_2 =(0.6)^2/(0.3)^2
▭(K_1/K_2 =4)

S6. Ans.(b)
Sol. In loose saturated sand on disturbance soil molecules came closer and volume decreases is setup hence positive pore pressure is setup as a result effective stress reduces and sudden loss in shear strength is observed such phenomenon is called liquefaction of sands.

S7. Ans.(a)
Sol. The upstream slope of an earthen dam under steady seepage condition is equipotential line.

S8. Ans.(c)
Sol. Rankine assume back of wall is vertical and smooth where coulomb assume rough.

S9. Ans.(b)
Sol. Negative stain friction on a pile acts downward and reduces the load carrying copacity of the pile.

S10. Ans.(d)
Sol. Since the area is limited and there is no time period specified for population estimation, therefore logistic curve method will be the best.