Quiz: Civil Engineering 16 Mar 2021

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

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

Q1. A soil has a liquid of 40% and plasticity index of 20%. The plastic limit of the soil will be
(a) 20%
(b) 30%
(c) 40%
(d) 60%

Q2. A line load of infinite length has an intensity q per unit length. What is the vertical stress σ_z at a depth z below the earth at the centre of the load?
(a) σ_z=2qz/π
(b) σ_z=2q/πz
(c) σ_z=2qz²/π
(d) σ_z=2q/πz²

Q3. Which one of the following pairs is INCORRECTLY matched?
(a) Air Valve – to check the water flow in pipes, in the directions
(b) Check valve – To release the accumulated air in pipelines.
(c) Scour valve – To drain or empty the pipe line section
(d) Surge arrestor – control of water hammer in pipe lines

Q4. The time elapsed between the moment water added to the ordinary Portland cement and the time when the cement completely loses in plasticity and can resist certain definite pressure is termed as:
(a) Initial setting time
(b) Final setting time
(c) Hydration time
(d) Gestation period

Q5. Modular ratio is denoted by:
(a) m=280/(3σ_cbc )
(b) m=280/(5σ_cbc )
(c) m=2800/(3σ_cbc )
(d) m=300/(3σ_cbc )

Q6. The woodworks should be measured to nearest
(a) 0.0014 m
(b) 0.002 m
(c) 0.003 m
(d) 0.004 m

Q7. In an experiment it found that the bulk modulus of a material is equal to its shear modulus. This poisson’s ratio is.
(a) 0.125
(b) 0.250
(c) 0.375
(d) 0.500

Q8. Property of a fluid by which molecules of different kind of fluids are attracted to each other is called _.
(a) adhesion
(b) cohesion
(c) viscosity
(d) compressibility

Q9. A 30 m metric chain is found to be 0.1 m too short throughout the measurement. If the distance measured is recorded as 300 m, then the actual distance measured will be
(a) 300.1 m
(b) 301.0 m
(c) 299.0 m
(d) 310.0 m

Q10. A shear test was conducted on a soil sample. At failure, the ratio of (σ_1-σ_2)/2 to (σ_1+σ_2)/2 is equal to unity. Which of the following shear tests represents this condition?
(a) Undrained triaxial tensile test
(b) Drained triaxial compression test
(c) Undrained triaxial compression test
(d) Unconfined compression test

Solutions
S1. Ans.(a)
Sol. Given
w_L=40%
I_P = 20%
w_P= ?
I_P=w_L-w_P
20%=40%-W_P
▭(W_P=20%)

S2. Ans.(b)
Sol. A line load of infinite length has an intensity q per unit length then vertical stress (σ_z) at a depth Z below the earth is given by –
▭(σ_z=2q/πz)

S3. Ans.(b)
Sol. Check value or reflux valve or non-returning valves are allowed the flow only in one direction only back flow is not permitted.

S4. Ans.(b)
Sol. Initial setting time → it is the time lapsed between addition of water and the time when cement paste starts loose its plasticity.
Final setting time → it is the time lapsed between addition of water and the time when cement paste completely loses its plasticity.

S5. Ans.(a)
Sol. ▭(Modular Ratio (m)=280/(3σ_cbc ))
σ_cbc = Permissible stress in concrete in bending compression.

S6. Ans.(b)
Sol. The woodworks should be measured nearest up to 0.002m or 2 mm.

S7. Ans.(a)
Sol. We know that, μ=(3K-2G)/(6K+2G)
But here, K = G,
∴ μ=(3-2)/(6+2)=1/8 = 0.125

S8. Ans.(a)
Sol. It is defined as-
Cohesion – an attractive force between same kind of fluid molecules.
Adhesion – an attractive force between different kind of fluid molecules.

S9. Ans.(c)
Sol. Correct length of chain (l) = 30 m.
Wrong length of chain (l’) = 30-0.1
= 29.9m.
Wrong length of measured line (L’) = 300 m.
Correct length of measured line (L) = ?
L×l×l^’×L^’
L×30=29.9×300
L=29.9/30×300
▭(L=299m.)

S10. Ans.(d)
Sol. According to question
(σ_1-σ_2)/2=(σ_1+σ_2)/2
σ_1-σ_2=σ_1+σ_2
▭(σ_2=0)
→ In unconfined compressive strength test confining pressure is zero therefore no rubber membrane required.