Engineering Jobs   »   Quiz : Civil engineering (16-02-2021)

# Quiz : Civil engineering (16-02-2021)

Quiz: Civil Engineering
Exam: NPCIL-SCINTIFIC ASSISTANT(CIVIL)
Topic: MISCELLANEOUS

Each question carries 1 mark
Negative marking: No negative marking
Time: 10 Minutes

Q1. Efflorescence in bricks causes due to
(a) Excessive burning of bricks
(b) high content of silt in crick clay
(c) high porosity of the bricks
(d) presence of soluble salt in parent clay

Q2. If a concrete column 200 × 200 mm in cross-section is reinforced with four steel bars of 1200 mm² total cross-sectional area. What is the safe load for the column if permissible stress in concrete is 5 N/mm² and E_s=15 E_c?
(a) 264 MN
(b) 274 MN
(c) 284 MN
(d) 294 MN

Q3. Maximum allowable shear stress in a section is 100 kg/cm². If bar is subjected to tensile force of 5000 kg and if the section is square shaped, what will be the dimension of side of the squares?
(a) 10 cm
(b) 5 cm
(c) 12 cm
(d) √12 cm

Q4. The Sequence of four stages of survey in a highway alignment is
(a) reconnaissance, map study, preliminary survey and detailed survey
(b) map study, preliminary survey, reconnaissance and detailed survey
(c) map study, reconnaissance, preliminary survey and detailed survey
(d) preliminary survey, map study reconnaissance and detailed survey

Q5. The road intersection where all converging vehicles are forced to move round a large central island in one direction before they can weave out of traffic flow into their respective directions radiating from the central island is called as __.
(a) Clover leaf
(b) Staggered intersection
(c) Rotary intersection
(d) Skewed intersection

Q6. This is generally used for pre-mixing tar macadam in base course: –
(a) RT -1
(b) RT -2
(c) RT -3
(d) RT -4

Q7. Viscosity of a fluid with specific gravity 1.3 is measured to be 0.0034 Ns/m². Its kinematic viscosity, in m²/s, is___________:
(a) 2.6 × 10-6
(b) 4.4 × 10-6
(c) 5.8 × 10-6
(d) 7.2 × 10-6

Q8. Pressure in terms of metres of oil (specific gravity = 0.9) equivalent to 4.5 m of water is
(a) 4.05
(b) 5.0
(c) 3.6
(d) 0.298

Q9. 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

Q10. The batching tolerance for cement as per IS 456 is
(a) ±1%
(b) ±1.5%
(c) ±2%
(d) ±3%

SOLUTION

S1. Ans.(d)
Sol. Efflorescence in bricks causes due to presence of alkalies and soluble salt in parent clay.

S2. Ans.(c)
Sol. A_T=200×200
= 40000 mm²
A_sc=1200 mm²
σ_cc=5 N\/mm^2
E_s=15 E_c
Modular Ratio (m) = E_s/E_c
▭(m=15)
σ_sc=m×σ_cc
=15×5
=75 N\/mm^2
Safe load (p) = σ_cc Ac+σ_sc Asc
=5×(40,000-1200)+75×1200
=284000 N
▭(P=284 KN)

S3. Ans.(b)
Sol. Max^m Allowable shear stress τ_max= 100 kg/cm²
Tensile force (f) = 5000 kg
τ_max=(σ_1-σ_3)/2
=(σ-0)/2
τmax=σ/2
τmax =F/2A
100=5000/(2×A)
▭(A=25 cm^2 )
If. Shape is square
▭(a=5 cm)

S4. Ans.(c)
Sol. The sequence of four stages of survey in a highway alignment is
Map study → Reconnaissance → preliminary
Survey → Detailed Survey

S5. Ans.(c)
Sol. The road intersection when all converging vehicles are forced to move round a large central island in the one direction before they can weave out to traffic flow into their respective directions radiating from the central island is called as rotary intersection.
S6. Ans.(d)
Sol. RT-4 is generally used for pre-mixing tar macadam in base course.

S7. Ans. (a)
Sol. Dynamic viscosity (μ) = 0.0034 (N-S)/m²
Specific gravity (G) = 1.3
Kinematic viscosity (ν) = μ/ρ
ν = μ/(ρ_w G)
ν = 0.0034/(1000×1.3 )
= 2.61 × 10^(-6) m²/sec.
S8. Ans. (b)
Sol. (ρgh) oil = (ρgh) water
1000 × 0.9 × 9.81× h = 1000 × 9.81 × 4.5

h = 5 m of oil

S9. Ans.(b)
Sol. Initial setting time → it is the time lapsed between addition of water and the cement paste starts loosing its plasticity.

Final setting time → it is the time lapsed between the addition of water and the time when cement completely loses it’s plasticity.

S10. Ans.(c)
Sol.
Material Batching tolerance