Quiz: Civil Engineering 21 july 2020

Quiz: Civil Engineering
Exam: UPPSC-AE
Topic: Miscellaneous

Each question carries 1 mark
Negative marking: 1/3 mark
Time: 10 Minutes

Q1. Match list-I (Material) with List – II (young’s   modulus):

List – I                                                                   List – II

  1. Brass                                                                   1.  83-170 GPa
  2. Steel                                                                    2. 96-110 GPa
  3. Aluminium alloys                                                3. 70-79 GPa
  4. Cast iron                                                              4. 48-83 GPa
  5.                                                                                190-210 GPa

Codes:

A             B             C             D

(a)           2              5              3              1

(b)          2              3              5              4

(c)           2              3              5              1

(d)          2              5              3              4

Q2. Compression members always tend to buckle in the direction of the :
(a) Perpendicular to the axis of load,
(b) Minimum cross-section
(c) Least radius of gyration
(d) Axis of load

Q3.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

Q4. A steel plate is 30 cm wide and 10 mm thick. if the diameter of the bolt hole is 18 mm, the net sectional area of the plate is
(a)18 Cm2
(b)28.20Cm2
(c)28.05 Cm2
(d)28 Cm2

Q5. The factor of safety for steel as compared to concrete is ……………
(a) Higher
(b) Same
(c) Lower
(d) None of these

Q6. The operation of removal of impurities of clay adhering to iron ore is known as __________.
(a) Calcination
(b) Purification
(c) Dressing
(d) Refining

Q7. As per IS specifications, the nominal concrete cover for moderate exposure should not be less than…………..
(a) 20 mm
(b) 30 mm
(c) 45 mm
(d) 50 mm

Q8. Consider the following statement regarding characteristic strength of concrete:
“the test result of the sample shall be the average of the strength of x specimens. The individual variation should not be more than ± Y% of the average.”
(a) 5, 15 respectively
(b) 5, 5 respectively
(c) 3, 5 respectively
(d) 3, 15 respectively

Q9. The compressive strength of ordinary Portland cement after 3 days should not be less than:
(a) 50 kg/cm²
(b) 100 kg/cm²
(c) 115 kg/cm²
(d) 150 kg/cm²

Q10. The life of teak wood doors and windows is usually taken to be………..
(a) 80 year
(b) 60 year
(c) 40 year
(d) 20 year

SOLUTION

S1. Ans.(a)

Sol.

Material Modules of Elasticity (GPa)
Alluminium alloys 70-79
Brass 96-110
Bronze 96-120
Cast Iron 83-170

S2. Ans.(c)
Sol. Compression members always tends to buckle in the direction of the least radius of gyration.

S3. Ans.(b)
Sol. In loose saturated sands on disturbance soil molecules came closer and volume decreases and hence positive pore pressure is set up, as a result effective stress reduces and sudden loss in shear strength is observed which results into failure. Such phenomenon is called liquefaction of sands.

S4. Ans.(c)
Sol.
Anet = (B – n ×dn) × t
(n = 1)
dn = 18 + 2 = 20 mm
B = 30 cm = 3000 mm
∴ Anet = (300-1×20) × 10 = 28 cm².

S5. Ans.(c)
Sol. factor of safety of steel ⇒1.15
Factor of safety of concrete ⇒ 1.5
→ Due to variability in strength of concrete due to poor quality control, poor work man ship etc, higher factor of safety is given for concrete in comparison to steel.

S6. Ans.(b)
Sol. Purification → It is the process to removing of impurities of clay adhering to iron ore.

S7. Ans.(b)

S7. Ans.(b)

Sol.

Exposure condition Minimum grade Minimum cover
Mild M20 20mm
Moderate M25 30mm
Sever M30 45mm
Very sever M35 50mm
Extreme M40 75mm

 

S8. Ans.(d)
Sol. the test result of the sample shall be average of the strength of 3 specimens. The individual variation should not be more than ± 15% of the average.

S9. Ans.(d)

Sol.

Minimum compressive strength in N/mm²
Days 1 day 3 days 7 days 28 days  
OPC 16.0 22.0 33.0  

S10. Ans.(c)
Sol. Teak is most durable and valuable Timber. The colour of teak wood is dark yellow. The life of teak wood doors and window is usually taken to be 40 years.

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